双语教学中的生物化学词汇

双语生物化学词汇

Gloary of Biochemistry Bilingually

A Absolute configuration（绝对构型） The configuration of four different substituent groups around an asymmetric carbon atom, in relation to u- and i.-glyceraldehyde.Absorption（吸收）: transport of the products of digestion from the intestinal tract into the blood.Acceptor control（受体控制）: The regulation of the rate of respiration by the availability of ADP as phosphate group acceptor.Acceory pigments（辅助色素）: Visible light-absorbing pigments (carotenoids, xanthophyll, and phycobilins藻胆素) in plants and photosynthetic bacteria that complement chlorophylls in trapping energy from sunlight.Acidosis（酸中毒）: A metabolic condition in which the capacity of the body to buffer is diminished; usually accompanied by decreased blood pH.Actin（肌动蛋白）: A protein making up the thin filaments（细丝） of muscle; also an important component of the cytoskeleton of many eukaryotic cells.Activation energy (ΔG*)（活化能）: The amount of energy (in joules) required to convert all the molecules in 1 mole of a reacting substance from the ground state to the transition state.Activator: （活化物、激活剂）(1) A DNA-binding protein that positively regulates the expreion of one or more genes; that is, transcription rates increase when an activator is bound to the DNA.(2) A positive modulator of an allosteric enzyme.Active site:（活性部位） The region of an enzyme surface that binds the substrate molecule and catalytically transforms it; also known as the catalytic site.Active transport:（主动运输） Energy-requiring transport of a solute acro a membrane in the direction of increasing concentration.Activity:（活度） The true thermodynamic activity or potential of a substance, as distinct from its molar concentration.Activity coefficient:（活度系数） The factor by which the numerical value of the concentration of a solute must be multiplied to give its true thermodynamic activity.Adenosine 3\',5\'-cyclic monophosphate: See cyclic AMP.Adenosine diphosphate: See ADP.Adenosine triphosphate: See ATP.

Adipocyte: （脂肪细胞）An animal cell specialized for the storage of fats (triacylglycerols).Adipose tiue:（脂肪组织） Connective tiue specialized for the storage of large amounts of triacylglycerols.ADP (adenosine diphosphate): A ribonucleoside diphosphate serving as phosphate group acceptor in the cell energy cycle.Aerobe:（需氧生物） An organism that lives in air and uses oxygen as the terminal electron acceptor in respiration.Aerobic: Requiring or occurring in the presence of oxygen.Alcohol fermentation:（乙醇发酵） The anaerobic conversion of glucose to ethanol via glycolysis.See also fermentation.Aldose: （醛糖）A simple sugar in which the carbonyl carbon atom is an aldehyde; that is, the carbonyl carbon is at one end of the carbon chain.Alkalosis:（碱中毒） A metabolic condition in which the capacity of the body to buffer is diminished; usually accompanied by an increase in blood pH.Allosteric enzyme:（变/别构效应） A regulatory enzyme, with catalytic activity modulated by the noncovalent binding of a specific metabolite at a site other than the active site.Allosteric protein: （变/别构蛋白） A protein (generally with multiple subunits) with multiple ligand-binding sites, such that ligand binding at one site affects ligand binding at another.Allosteric site: （变/别构部位） The specific site on the surface of an allosteric enzyme molecule to which the modulator or effector molecule is bound.α helix:（α-螺旋）A helical conformation of a polypeptide chain, usually right-handed, with maximal intrachain hydrogen bonding; one of the most common secondary structures in proteins.Ames test: A simple bacterial test for carcinogens, based on the aumption that carcinogens are mutagens.Amino acid activation: （氨基酸活化）ATP-dependent enzymatic esterification of the carboxyl group of an amino acid to the 3\'-hydroxyl group of its corresponding tRNA.Amino acids:（氨基酸） an Amino-substituted carboxylic acids, the building blocks of proteins.Amino-terminal residue:（氨基末端残基） The only amino acid residue in a polypeptide chain with a free a-amino group; defines the amino terminus of the polypeptide.Aminoacyl-tRNA: （氨酰tRNA）An aminoacyl ester of a tRNA.Aminoacyl-tRNA synthetases: （氨酰tRNA合成酶） Enzymes that catalyze synthesis of an aminoacyl-tRNA at the expense of ATP energy.Aminotransferases:（氨基转移酶） Enzymes that catalyze the transfer of amino groups fromα-amino to α-keto acids; also called transaminases.Ammonotelic: （排氨的）Excreting exce nitrogen in the form of ammonia.Amphibolic pathway: （双向代谢途径）A metabolic pathway used in both catabolism and anabolism.

2 Amphipathic: （双亲的）Containing both polar and nonpolar domains.Ampholyte:（两性电解质） A substance that can act as either a base or an acid.Amphoteric:（两性的） Capable of donating and accepting protons, thus able to serve as an acid or a base.Anabolisim:（合成代谢） The phase of intermediary metabolism concerned with the energy-requiring biosynthesis of cell components from smaller precursors.Anaerobe: （厌氧生物） An organism that lives without oxygen.Obligate anaerobes（专性厌氧生物） die when exposed to oxygen.Anaerobic: （厌氧的）Occurring in the absence of air or oxygen.Anaplerotic reaction: （回补反应）An enzyme-catalyzed reaction that can replenish the supply of intermediates in the citric acid cycle.Angstrom (Ǻ): （唉）A unit of length (10-8cm) used to indicate molecular dimensions.Anhydride:（酸酐） The product, of the condensation of two carboxyl or phosphate groups in which the elements of water are eliminated to form a compound with the general structure R—X—0—X—R, where X is either carbon or phosphorus.Anion-exchange resin:（阴离子交换树脂） A polymeric resin with fixed cationic groups; used in the chromatographic separation of anions.Anomers:（异头物、端基异构体） Two stereoisomers of a given sugar that differ only in the configuration about the carbonyl (anomeric) carbon atom.Antibiotic:（抗生素） One of many different organic compounds that are formed and secreted by various species of microorganisms and plants, are toxic to other species, and presumably have a defensive function.Antibody:（抗体） A defense protein synthesized by the immune system of vertebrates.See also immunoglobulin.Anticodon:（反密码子） A specific sequence of three nucleotides in a tRNA, complementary to a codon for an amino acid in an mRNA.Antigen:（抗原） A molecule capable of eliciting the synthesis of a specific antibody in vertebrates.Antiparallel:（反平行） Describing two linear polymers that are opposite in polarity or orientation.Antiport: （反向转运）Cotransport of two solutes acro a membrane in opposite directions.Apoenzyme:（酶蛋白） The protein portion of an enzyme, exclusive of any organic or inorganic cofactors or prosthetic groups that might be required for catalytic activity.Apolipoprotein:（脱辅基脂蛋白） The protein component of a lipoprotein.Apoprotein: （脱辅基蛋白）The protein portion of a protein, exclusive of any organic or inorganic cofactors or prosthetic groups that might be required for activity.Apoptosis:（细胞凋亡） (app\'-a-toe\'-sis) Programmed cell death, in which a cell brings

3 about its own death and lysis, signaled from outside or programmed in its genes, by systematically degrading its own macromolecules.Arrestin:（抑制蛋白） A family of proteins that bind to the phosphorylated carboxyl-terminal region of serpentine receptors, preventing their interactions with G proteins and thereby terminating the signal through those receptors.Asymmetric carbon atom: （不对称碳原子）A carbon atom that is covalently bonded to four different groups and thus may exist in two different tetrahedral configurations.ATP (adenosine triphosphate): A ribonucleoside 5\'-triphosphate functioning as a phosphate group donor in the cell energy cycle; carries chemical energy between metabolic pathways by serving as a shared intermediate coupling endergonic and exergonic reactions.ATP synthase: （ATP合酶）An enzyme complex that forms ATP from ADP and phosphate during oxidative phosphorylation in the inner mitochondrial membrane or the bacterial plasma membrane, and during photophosphorylation in chloroplasts.ATPase: （ATP酶）An enzyme that hydrolyzes ATP to yield ADP and phosphate; usually coupled to some proce requiring energy.Attenuator: （弱化子）An RNA sequence involved in regulating the expreion of certain genes; functions as a transcription terminator.Autotroph:（自养生物） An organism that can synthesize its own complex molecules from very simple carbon and nitrogen sources, such as carbon dioxide and ammonia.Auxin:（植物生长素） A plant growth hormone.Auxotrophic mutant (auxotroph):（营养缺陷突变体） A mutant organism defective in the synthesis of a given biomolecule, which must therefore be supplied for the organism\'s growth.Avogadro\'s number: The number of molecules in a gram molecular weight (a mole) of any compound (6.02 × 1023).B Back-mutation:（回复突变） A mutation that causes a mutant gene to regain its wild-type base sequence.Bacteriophage (phage): （噬菌体）A virus capable of replicating in a bacterial cell.Basal metabolic rate: （基础代谢率）The rate of oxygen consumption by an animal\'s body at complete rest, long after a meal.Base pair:（碱基对） Two nucleotides in nucleic acid chains that are paired by hydrogen bonding of their bases; for example, A with T or U, and G with C.β conformation:（β构象）、An extended, zigzag arrangement of a polypeptide chain; a common secondary structure in proteins.β oxidation: （β氧化）Oxidative degradation of fatty acids into acetyl-CoA by succeive oxidations at the β-carbon atom.β-turn:（β转角）A type of secondary structure in polypeptides consisting of four amino

4 acid residues arranged in a tight turn so that the polypeptide turns back on itself.Bilayer:（双分子层） A double layer of oriented amphipathic lipid molecules, forming the basic structure of biological membranes.The hydrocarbon tails face inward to form a continuous nonpolar phase.Bile salts:（胆酸盐） Amphipathic steroid derivatives with detergent properties, participating in digestion and absorption of lipids.Binding energy:（吸附能） The energy derived from noncovalent interactions between enzyme and substrate or receptor and ligand.Binding site: （结合部位）The crevice or pocket on a protein in which a ligand binds.Biocytin:（生物胞素） The conjugate amino acid residue arising from covalent attachment of biotin, through an amide linkage, to a Lys residue.Biomolecule:（生物分子） An organic compound normally present as an eential component of living organisms.Biopterin: （生物喋呤）An enzymatic cofactor derived from pterin and involved in certain oxidation-reduction reactions.Biosphere:（生物圈） All the living matter on or in the earth, the seas, and the atmosphere.Biotin:（生物素） A vitamin; an enzymatic cofactor involved in carboxylation reactions.Bond energy:（键能） The energy required to break a bond.Branch migration:（分支迁移） Movement of the branch point in branched DNA formed from two DNA molecules with identical sequences.See also Holliday intermediate.Buffer: （缓冲液）A system capable of resisting changes in pH, consisting of a conjugate acid-base pair in which the ratio of proton acceptor to proton donor is near unity.C Calorie:（卡） The amount of heat required to raise the temperature of 1.0 g of water from 14.5 to 15.5 °C.One calorie (cal) equals 4.18 joules (J).Calvin cycle:（Calvin循环） The cyclic pathway used by plants to fix carbon dioxide and produce triose phosphates.cAMP: See cyclic AMP.cAMP receptor protein (CRP): （cAMP受体蛋白）A specific regulatory protein that controls initiation of transcription of the genes producing the enzymes required for a bacterial cell to use some other nutrient when glucose is lacking.Also called catabolite gene activator protein (CAP)，降解物基因活化蛋白.CAP: See catabolite gene activator protein.Capsid:（衣壳） The protein coat of a virion or virus particle.Carbanion:（碳负离子） A negatively charged carbon atom.Carbocation: （碳正离子） A positively charged carbon atom; also called a carbonium

5 ion.Carbon-aimilation reactions:（碳同化反应） Reaction sequences in which atmospheric CO2 is converted into organic compounds.Carbon-fixation reaction:（固碳反应） The reaction catalyzed by rubisco during photosynthesis, or by other carboxylases, in which atmospheric CO2 is initially incorporated into an organic compound.Carboxyl-terminal residue:（羧基末端残基） The only amino acid residue in a polypeptide chain with a free a-carboxyl group; defines the carboxyl terminus of the polypeptide.Carotenoids:（类葫罗卜素） Lipid-soluble photosynthetic pigments made up of isoprene units.Catabolism:（分解代谢） The phase of intermediary metabolism concerned with the energy-yielding degradation of nutrient molecules.Catabolite gene activator protein (CAP): See cAMP receptor protein.Catalytic site: （催化部位）See active site.Catecholamines:（儿茶酚胺类） Hormones, such as epinephrine, that are amino derivatives of catechol.Catenane:（连环体） Circular polymeric molecules with a noncovalent topological link resembling the links of a chain.Cation-exchange resin: （阳离子交换树脂）An insoluble polymer with fixed negative charges; used in the chromatographic separation of cationic substances.cDNA: See complementary DNA.Central dogma:（中心法则） The organizing principle of molecular biology: genetic information flows from DNA to RNA to protein.Centromere:（着丝粒） A specialized site within a chromosome, serving as the attachment point for the mitotic or meiotic spindle.Cerebroside(脑苷酯) Sphingolipid containing one sugar residue as a head group.Channeling:（生物合成途径限制作用) The direct transfer of a reaction product (common intermediate) from the active site of one enzyme to the active site of a different enzyme catalyzing the next step in a sequential pathway.Chemiosmotic coupling:（化学渗透偶联） Coupling of ATP synthesis to electron transfer via an electrochemical H+ gradient acro a membrane.Chemotaxis（向化性）: A cell\'s sensing of and movement toward, or away from, a specific chemical agent.Chemotroph:（化能生物） An organism that obtains energy by metabolizing organic compounds derived from other organisms.Chiral center: （手性中心）An atom with substituents arranged so that the molecule is not superimposable on its mirror image.Chiral compound: （手性化合物） A compound that contains an asymmetric center

6 (chiral atom or chiral center) and thus can occur in two nonsuperimposable mirror-image forms (enantiomers).Chlorophylls: （叶绿素）A family of green pigments functioning as receptors of light energy in photosynthesis; magnesium-porphyrin complexes.Chloroplasts: （叶绿体） Chlorophyll-containing photosynthetic organelles in some eukaryotic cells.Chromatin:（染色质） A filamentous complex of DNA, histones, and other proteins, constituting the eukaryotic chromosome.Chromatography:（层析） A proce in which complex mixtures of molecules are separated by many repeated partitionings between a flowing (mobile) phase and a stationary phase.Chromosome:（染色体） A single large DNA molecule and its aociated proteins, containing many genes; stores and transmits genetic information.Chylomicron: （乳糜微粒）A plasma lipoprotein consisting of a large droplet of triacylglycerols stabilized by a coat of protein and phospholipid; carries lipids from the intestine to the tiues.cis and trans isomers: （顺反异构体）See geometric isomers.Cistron:（顺反子） A unit of DNA or RNA corresponding to one gene.Citric acid cycle: （柠檬酸循环）A cyclic system of enzymatic.reactions for the oxidation of acetyl residues to carbon dioxide, in which formation of citrate is the first step; also known as the Krebs cycle or tricarboxylic acid cycle.Clones:（克隆） The descendants of a single cell.Cloning: The production of large numbers of identical DNA molecules, cells, or organisms, from a single ancestral DNA molecule, cell, or organism.Closed system: （封闭系统）A system that exchanges neither matter nor energy with the surroundings.See also system.Cobalamin:（钴胺素） See cocnzyme B12.Codon: （密码子）A sequence of three adjacent nucleotides in a nucleic acid that codes for a specific amino acid.Coenzyme:（辅酶） An organic cofactor required for the action of certain enzymes; often contains a vitamin as a component.Coenzyme A: （辅酶A） A pantothenic acid-containing coenzyme serving as an acyl group carrier in certain enzymatic reactions.Coenzyme B12: An enzymatic cofactor derived from the vitamin cobalamin, involved in certain types of carbon skeletal rearrangements.Cofactor(辅助因子) An inorganic ion or a coenzyme required for enzyme activity.Cognate:（相关的） Describing two biomolecules that normally interact; for example, an enzyme and its normal substrate, or a receptor and its normal ligand.Cohesive ends: （粘性末端）See sticky ends.

7 Cointegrate:（共整合） An intermediate in the migration of certain DNA transposons in which the donor DNA and target DNA are covalently attached.Colligative properties:（依数性） Properties of solutions that depend on the number of solute particles per unit volume; for example, freezing-point depreion.Common intermediate:（共同中间产物） A chemical compound common to two chemical reactions, as a product of one and a reactant in the other.Competitive inhibition:（竞争性抑制作用） A type of enzyme inhibition reversed by increasing the substrate concentration; a competitive inhibitor generally competes with the normal substrate or ligand for a protein\'s binding site.Complementary:（互补） Having a molecular surface with chemical groups arranged to interact specifically with chemical groups on another molecule.Complementary DNA (cDNA): A DNA used in DNA cloning, usually made by reverse transcriptase; complementary to a given mRNA.Configuration:（构型） The spatial arrangement of an organic molecule that is conferred by the presence of either (1) double bonds, about which there is no freedom of rotation, or (2) chiral centers, around which substituent groups are arranged in a specific sequence.Configurational isomers cannot be interconverted without breaking one or more covalent bonds.Conformation:（构象） The spatial arrangement, of substituent groups that are free to aume different positions in space, without breaking any bonds, because of the freedom of bond rotation.Conjugate acid-base pair:（共扼酸碱对） A proton donor and its corresponding deprotonated species; for example, acetic acid (donor) and acetate (acceptor).Conjugate redox pair: （共扼氧还对） An electron donor and its corresponding electron acceptor form; for example, Cu+ (donor) and Cu2+ (acceptor), or NADH (donor) and NAD+ (acceptor).Conjugated protein:（结合蛋白质） A protein containing one or more prosthetic groups.Consensus sequence:（一致序列） A DNA or amino acid sequence consisting of the residues that occur most commonly at each position within a set of similar sequences.Conservative substitution:（保守性置换） Replacement of an amino acid residue in a polypeptide by another residue with similar properties; for example, substitution of Glu by Asp.Constitutive enzymes:（组成酶） Enzymes required at all times by a cell and present at some constant level; for example, many enzymes of the central metabolic pathways.Sometimes called house-keeping enzymes.Contour length (外形长度): The length of a helical polymeric molecule as measured along the molecule\'s helical axis.Corticosteroids（皮质类固醇激素） Steroid hormones formed by the adrenal cortex.Cotransport:（共转运） The simultaneous transport, by a single transporter, of two

8 solutes acro a membrane.See antiport, symport.Coupled reactions:（偶联反应） Two chemical reactions that have a common intermediate and thus a means of energy transfer from one to the other.Covalent bond: （共价键）A chemical bond that involves sharing of electron pairs.Cristae: （嵴）Infoldings of the inner mitochondrial membrane.CRP（cAMP受体蛋白）See cAMP receptor protein.Cyclic AMP (cAMP): A second meenger within cells; its formation by adenylyl cyclase is stimulated by certain hormones or other molecular signals.Cyclic electron flow:（循环电子流） In chloroplasts, the light-induced flow of electrons originating from and returning to photosystem I.Cyclic photophosphorylation: （循环光合磷酸化） ATP synthesis driven by cyclic electron flow through photosystem I.Cyclin:（细胞周期蛋白） One of a family of proteins that activate cyclin-dependent protein kinases and thereby regulate the cell cycle.Cytochromes:（细胞色素） Heme proteins serving as electron carriers in respiration, photosynthesis, and other oxidation-reduction reactions.Cytokine:（细胞因子） One of a family of small secreted proteins (such as interleukins or interferons) that activate cell division or differentiation by binding to plasma membrane receptors in sensitive cells.Cytokinesis:（胞质分裂） The final separation of daughter cells following mitosis.Cytoplasm:（细胞质） The portion of a cell\'s contents outside the nucleus but within the plasma membrane; includes organelles such as mitochondria.Cytoskeleton:（细胞骨架） The filamentous network providing structure and organization to the cytoplasm; includes actin filaments, microtubules, and intermediate filaments.Cytosol:（细胞浆） The continuous aqueous phase of the cytoplasm, with its diolved solutes; excludes the organelles such as mitochondria.D Dalton:（道尔顿） The weight of a single hydrogen atom (1.66 x I0-24 g).Dark reactions:（暗反应） See carbon-aimilation reactions.De novo pathway:（从头合成） Pathway for synthesis of a biomolecule, such as a nucleotide, from simple precursors; as distinct from a salvage pathway.Deamination:（脱氨基作用） The enzymatic removal of amino groups from biomolecules such as amino acids or nucleotides.Degenerate code:（兼并密码） A code in which a single element in one language is specified by more than one element in a second language.Dehydrogenases:（脱氢酶类） Enzymes catalyzing the removal of pairs of hydrogen atoms from their substrates.Deletion mutation:（删除突变） A mutation resulting from the deletion of one or more

9 nucleotides from a gene or chromosome.Denaturation:（变性） Partial or complete unfolding of the specific native conformation of a polypeptide chain, protein, or nucleic acid.Denatured protein:（变性蛋白） A protein that has lost its native conformation by exposure to a destabilizing agent such as heat or detergent.Deoxyribonucleic acid; See DNA.Deoxyribonucleotides:（脱氧核糖核苷酸） Nucleotides containing 2-deoxyribose as the pentose component.Desaturases:（去饱和酶） Enzymes that catalyze the introduction of double bonds into the hydrocarbon portion of fatty acids.Desolvation:（脱水） In aqueous solution, the release of bound water surrounding a solute.Dextrorotatory isomer:9右旋异构体） A stercoisomer that rotates the plane of plane-polarized light clockwise.Diabetes mellitus:（糖尿病） A metabolic disease resulting from insulin deficiency; characterized by a failure in glucose transport from the blood into cells at normal glucose concentrations.Dialysis: （透析）Removal of small molecules from a solution of a macromolecule, by allowing them to diffuse through a semipermeable membrane into water.Differential centrifugation: （差速离心）Separation of cell organelles or other particles of different size by their different rates of sedimentation in a centrifugal field.Differentiation:（分化） Specialization of cell structure and function during embryonic growth and development.Diffusion:（扩散） The net movement, of molecules in the direction of lower concentration.Digestion:（消化） Enzymatic hydrolysis of major nutrients in the gastrointestinal system to yield their simpler components.Diploid:（二倍体） Having two sets of genetic information; describing a cell with two chromosomes of each type.Dipole;（双极分子） A molecule having both positive and negative charges.Diprotic acid: An acid having two diociable protons.Disaccharide:（二糖） A carbohydrate consisting of two covalently joined monosaccharide units.Diociation constant:（解离常数） (1) An equilibrium constant (Kd)for the diociation of a complex of two or more biomolecules into its components; for example, diociation of a substrate from an enzyme.(2) The diociation constant (Ka) of an acid, describing its diociation into its conjugate base and a proton.Disulfide bridge: (二硫桥)A covalent cro link between two polypeptide chains formed by a cystine residue (two Cys residues). 0

1 DNA (deoxyribonucleic acid)： A polynucleotide having a specific sequence of deoxyribonucleotide units covalently joined through 3\', 5\'-phosphodiester bonds; serves as the carrier of genetic information.DNA chimera:（DNA嵌合） A DNA containing genetic information derived from two different species.DNA cloning: Sec cloning.DNA library:（DNA文库） A collection of cloned DNA fragments.DNA ligase：（DNA连接酶） An enzyme that creates a phosphodiester bond between the 3\' end of one DNA segment, and the 5\' end of another.DNA looping: （DNA出环）The interaction of proteins bound at distant sites on a DNA molecule so that the intervening DNA forms a loop.DNA microarray:（DNA微阵列） A collection of DNA sequences immobilized on a solid surface, with individual sequences laid out in patterned arrays that can be probed by hybridization.DNA polymerase:（DNA聚合酶） An enzyme that catalyzes template-dependent synthesis of DNA from its deoxyribonucleoside 5\'-triphosphate precursors.DNA replicase system：（DNA复制酶系统） The entire complex of enzymeH and specialized proteins required in biological DNA replication.DNA supercoiling:（DNA超螺旋化） The coiling of DNA upon itself, generally as a result of bending, underwinding, or overwinding of the DNA helix.DNA transposition:（DNA转座） See transposition.domain:（结构域） A distinct structural unit of a polypeptide; domains may have separate functions and may fold as independent, compact units.Double helix:（双螺旋） The natural coiled conformation of two complementary, antiparallel DNA chains.Double-reciprocal plot:（双倒数作图） A plot, of 1/Vo versus 1/[S], which allows a more accurate determination of Vmax and Km than a plot of V versus [S]; also called the Lineweaver-Burk plot, E E\'°: 标准还原电位 See standard reduction potential.E.coli (Escherichia coli): （大肠杆菌）A common bacterium found in the small intestine of vertebrates; the most well-studied organism.Electrochemical gradient:（电化学梯度） The sum of the gradients of concentration and of electric charge of an ion acro a membrane; the driving force for oxidative phosphorylation and photophosphorylation.Electrochemical potential: （电化学势）

The energy required to maintain a separation of charge and of concentration acro a membrane.Electrogenic: （生电的）Contributing to an electrical potential acro a membrane. 1 1

Electron acceptor:（电子受体） A substance that receives electrons in an oxidation-reduction reaction.Electron carrier:（电子载体） A protein, such as a flavoprotein or a cytochrome, that can reversibly gain and lose electrons; functions in the transfer of electrons from organic nutrients to oxygen or some other terminal acceptor.Electron donor:（电子供体） A substance that donates electrons in an oxidation-reduction reaction.Electron transfer:（电子转移） Movement of electrons from substrates to oxygen via the carriers of the respiratory (electron transfer) chain.Electrophile:（亲电剂） An electron-deficient group with a strong tendency to accept electrons from an electron-rich group (nucleophile).Electrophoresis（电泳）: Movement of charged solutes in response to an electrical field; often used to separate mixtures of ions, proteins, or nucleic acids.Electroporation:（电穿孔法） Introduction of macromolecules into cells after rendering the cells transiently permeable by the application of a high-voltage pulse.Elongation factors:（延长因子） Specific proteins required in the elongation of polypeptide chains by ribosomes.Eluate:（流出液） The effluent from a chromatographic column.Enantiomers:（对映异构体） Stereoisomers that are nonsuperimposable mirror images of each other.End-product inhibition: See feedback inhibition.Endergonic reaction(耗能反应): A chemical reaction that consumes energy (that is, for which ΔG is positive).Endocrine glands:（内分泌腺） Groups of cells specialized to synthesize hormones and secrete them into the blood to regulate other types of cells.Endocytosis:（内吞体） The uptake of extracellular material by its inclusion within a vesicle formed by an invagination of the plasma membrane.Endonuclease:（内切核酸酶） An enzyme that hydrolyzes the interior phosphodiester bonds of a nucleic acid; that is, it acts at points other than the terminal bonds.Endoplasmic reticulum:（内质网） An extensive system of double membranes in the cytoplasm of eukaryotic cells; it encloses secretory channels and is often studded with ribosomes (rough endoplasmic reticulum).Endothermic reaction:（吸热反应） A chemical reaction that takes up heat (that is, for which ΔH is positive).Energy charge:（能荷） The fractional degree to which the ATP/ADP/AMP system is filled with high-energy phosphate groups.Energy coupling:（能量偶联） The transfer of energy from one proce to anotlier.Enhancers: （增强子）DNA sequences that facilitate the expreion of a given gene; 2 1

may be located a few hundred, or even thousand, base pairs away from the gene.Enthalpy (H):（焓） The heat.content of a system.Enthalpy change (ΔH): （焓变）For a reaction, is approximately equal to the difference between the energy used to break bonds and the energy gained by the formation of new ones.Entropy (S):（熵） The extent of randomne or disorder in a system.Enzyme：（酶） A biomolecule, either protein or RNA, that catalyzes a specific chemical reaction.It does not affect the equilibrium of the catalyzed reaction; it enhances the rate of a reaction by providing a reaction path with a lower activation energy.Enzyme cascade:（酶级联） A series of reactions, often involved in regulatory events, in which one enzyme activates another (often by phosphorylation), which activates a third, and so on.The effect, of a catalyst activating a catalyst is a large amplification of the signal that initiated the cascade.Epimerases:（表异构酶） Enzymes that catalyze the reversible interconveraion of two epimers.Epimers: （表异构体） Two stereoisomers differing in configuration at one asymmetric center, in a compound having two or more asymmetric centers.Epithelial cell:（上皮细胞） Any cell that forms part of the outer covering of an organism or organ.Epitope:（抗原决定族） An antigenic determinant; the particular chemical group or groups within a macromolecule (antigen) to which a given antibody binds.Equilibrium:（平衡） The state of a system in which no further net change is occurring; the free energy is at a minimum.Equilibrium constant (K\'eq) （平衡常数）A constant, characteristic for each chemical reaction; relates the specific concentrations of all reactants and products at equilibrium at a given temperature and preure.Erythrocyte:（红细胞） A cell containing large amounts of hemoglobin and specialized for oxygen transport; a red blood cell.Escherichia coli: See E.coli.Eential amino acids:（必需氨基酸） Amino acids that cannot be synthesized by humans (and other vertebrates) and must be obtained from the diet.Eential fatty acids:（必需脂肪酸） The group of polyunsaturated fatty acids produced by plants, but not by humans; required in the human diet.Ethanol fermentation:（乙醇发酵） See alcohol fermentation.Eukaryote:（真核生物） A unicellular or multicellular organism with cells having a membrane-bounded nucleus, multiple chromosomes, and internal organelles.Excited state:（激发态） An energy-rich state of an atom or molecule; produced by the absorption of light energy.Exergonic reaction:（放能反应） A chemical reaction that proceeds with the release of 3 1

free energy (that is, for which ΔG is negative).

Exocytosis:（胞泌作用） The fusion of an intracellular vesicle with the plasma membrane, releasing the vesicle contents to the extracellular space.Exon:（外显子） The segment of a eukaryotic gene that encodes a portion of the final product of the gene; a portion that remains after posttranscriptional proceing and is transcribed into a protein or incorporated into the structure of an RNA.See intron.Exonuclease:（外切核酸酶） An enzyme that hydrolyzes only those phosphodiester bonds that are in the terminal positions of a nucleic acid.Exothermic reaction:（放热反应） A chemical reaction that releases heat (that is, for which A// is negative).Expreion vector:（表达载体） See vector.

F Facilitated diffusion: （协助扩散）Diffusion of a polar substance acro a biological membrane through a protein transporter; also called paive diffusion or paive transport.Facultative cells: （兼性需样氧细胞）Cells that can live in the presence or absence of oxygen.FAD (flavin adenine dinucleotide)：（黄素腺嘌呤二核苷酸） The coenzyme of some oxidation-reduction enzymes; it contains riboflavin.Fatty acid: （脂肪酸）A long-chain aliphatic carboxylic acid found in natural fats and oils; also a component of membrane phospholipids arid glycolipids.Feedback inhibition:（反馈抑制） Inhibition of an allosteric enzyme at the beginning of a metabolic sequence by the end product of the sequence; also known as end-product inhibition.Fermentation: （发酵）Knergy-yielding anaerobic breakdown of a nutrient molecule, such as glucose, without net oxidation; yields lactate, ethanol, or some other simple product.Fibroblast（成纤维细胞） A cell of the connective tiue that secretes connective tiue proteins such as collagen.Fibrous proteins:（纤维状蛋白质） Insoluble proteins that serve in a protective or structural role; contain polypeptide chains tliat generally share a common secondary structure.Fingerprinting: （指纹作图）See peptide mapping.First law of thermodynamics: The law staling that in all procees, the total energy of the universe remains constant.Fischer projection formulas:（Fischer投影式） See projection formulas.5\' end: The end of a nucleic acid that lacks a nucleotide bound at the 5\' position of the terminal residue. 4 1

Flagellum:(鞭毛 )A cell appendage used in propulsion.Bacterial flagella have a much simpler structure than eukaryotic flagella, which are similar to cilia.Flavin-linked dehydrogenases:(黄素脱氢酶) Dehydrogenases requiring one of the riboflavins.coenzymes, FMN or FAD.Flavin nucleotides:（黄素核苷酸） Nucleotide coenzymes (FMN and FAD) containing riboflavin.Flavoprotein(黄素蛋白 ) An enzyme containing a flavin nucleotide as a tightly bound prosthetic group.Fluid mosaic model:（流动镶嵌模型） A model describing biological membranes as a fluid lipid bilayer with embedded proteins; the bilayer exhibits both structural and functional asymmetry.Fluorescence:（荧光） Emiion of light by excited molecules as they revert to the ground state, FMN (flavin mononucleotide):（黄素单核苷酸） Riboflavin phosphate, a coenzyme of certain oxidation- reduction enzymes.Footprinting(足迹法) A technique for identifying the nucleic acid sequence bound by a DNA-or RNA-binding protein.Fractionation:（分级分离） The proce of separating the proteins or other components of a complex molecular mixture into fractions based on differences in their physical properties, such as size, net charge, and solubility.Frame shift:（移码） A mutation caused by insertion or deletion of one or more paired nucleotides, changing the reading frame of codons during protein synthesis; the polypeptide product has a garbled amino acid sequence beginning at the mutated codon.Free energy (G):（自由能） The component of the total energy of a system that can do work at constant temperature and preure.Free energy of activation ΔG‡ (活化自由能); See activation energy.Free-energy change ΔG(自由能变化): The amount of free energy released (negative ΔG) or absorbed (positive ΔG) in a reaction at constant temperature and preure.Free radical:（自由基） See radical.Functional group:（功能团） The specific atom or group of atoms that confers a particular chemical property on a biomolccule.Furanose:（呋喃糖） A simple sugar containing the five-membered furan ring.Fusion protein:（融合蛋白） (1) A family of proteins that facilitate membrane fusion.(2) The protein product of a gene created by the fusion of two distinct genes or portions of genes.Futile cycle:（无效循环） A set of enzyme-catalyzed cyclic reactions that results in release of thermal energy by the hydrolysis of ATP. 5 1

G G proteins:（G蛋白） A family of heterotrimeric GTP-binding proteins that act in intracellular signaling pathways.Commonly, ligand binding to a serpentine receptor induces the exchange of GTP for bound GDP, enabling the G protein to activate a downstream enzyme in a signaling pathway.G proteins have intrinsic GTPase activity, and therefore self-inactivate.ΔG’°: (标准自由能变化) See standard free-energy change.Gametes:（配子） Reproductive cells with a haploid gene content; sperm or egg cells.Gangliosides:（神经节苷脂） Sphingolipids, containing complex oligosaccharides as head groups; especially common in nervous tiue.Gel filtration:（凝胶过滤） See size-exclusion chromatography.（分子排阻层析） Gene: （基因）A chromosomal segment, that codes for a single functional polypeptide chain or RNA molecule.Gene expreion:（基因表达） Transcription, and in the case of proteins, translation, to yield the product of a gene; a gene is expreed when its biological product is present and active.Gene splicing:（基因拼接） The enzymatic attachment of one gene, or part.of a gene, to another.General acid-base catalysis:（广义酸碱催化） Catalysis involving proton transfer(s) to or from a molecule other than water.Genetic code:（遗传密码） The set of triplet code words in UNA (or mRNA) coding for the amino acids of proteins.Genetic information:（遗传信息） The hereditary information contained in a sequence of nucleotide bases in chromosomal DNA or RNA.Genetic map: （遗传图谱）A diagram showing the relative sequence and position of specific genes along a chromosome.Genome:（基因组） All the genetic information encoded in a cell or virus.Genomic library:（基因组文库）A DNA library containing DNA segments representing all (or most) of the sequences in an organism\'s genome.Genotype:（基因性或遗传型） The genetic constitution of an organism, as distinct from ils physical characteristics, or phenotype.Geometric isomers:（几何异构体） Isomers related by rotation about a double bond; also called cis and trans isomers.Germ-line cell (生殖系细胞) A type of animal cell that is formed early in embryogenesis and may multiply by mitosis or may produce, by meiosis, cells that develop into gametes (egg or sperm cells).Globular proteins：（球蛋白） Soluble proteins with a globular (somewhat rounded) shape.Glucogenic amino acids:（生糖氨基酸） Amino acids with carbon chains that can be 6 1

metabolically converted into glucose or glycogen via gluconeogenesis.Gluconeogenesis:(糖异生) The biosynthesis of a carbohydrate from simpler, noncarbohydrate precursors such as oxaloacetate（草酰乙酸） or pyruvate（丙酮酸）.Glycan:（聚糖） Another term for polysaccharide; a polymer-of monosaccharide units joined by glycosidic bonds, Glycerophospholipid:（甘油磷脂） An amphipathic lipid with a glycerol backbone; fatty acids are ester-linked to C-l and C-2 of glycerol, and a polar alcohol is attached through a phosphodiester linkage to C-3.Glycoconjugate:(复合糖) A compound containing a carbohydrate component bound covalently to a protein or lipid, forming a glycoprotein or glycolipids.Glycolipid:（ 糖脂） A lipid containing a carbohydrate group, Glycolysis:（糖酵解） The catabolic pathway by which a molecule of glucose is broken down into two molecules of pyruvate.Glycoprotein(糖蛋白) A protein containing a carbohydrate group.Glycosaminoglycan:（糖胺聚糖） A heteropolysaccharide of two alternating units: one is either N-acetylglucosamine or N-acetylgalactosamine; the other is a uronic acid (usually glucuronic acid).Formerly called mucopolysaccharide.(粘多糖) Glycosidic bonds:（糖苷键） Bonds between a sugar and another molecule (typically an alcohol, purine, pyrimidine, or sugar) through an intervening oxygen.Glyoxylate cycle:(乙醛酸循环) A variant of the citric acid cycle, for the net conversion of acetate into succinate and, eventually, new carbohydrate; present in bacteria and some plant cells.Glyoxysome:（乙醛酸体） A specialized peroxisome containing the enzymes of the glyoxylate cycle; found in cells of germinating seeds.Golgi complex: （高尔基复合体）A complex membranous organelle of eukaryotic cells; functions in the posttranslational modification of proteins and their secretion from the cell or incorporation into the plasma membrane or organellar membranes.Gram molecular weight:（克分子重量） The weight in grams of a compound that is numerically equal to its molecular weight; the weight of 1 mole.Grana:（基粒） Stacks of thylakoids（类囊体）, flattened membranous sacs or disks, in chloroplasts.Ground state:（基态） The normal, stable form of an atom or molecule; as distinct from the excited state.Group transfer potential:（基团转移力） A measure of the ability of a compound to donate an activated group (such as a phosphate or acyl group); generally expreed as the standard free energy of hydrolysis.H Half-life: （半衰期）The time required for the disappearance or decay of one-half of a 7 1

given component in a system.Haploid:（ 单倍体） Having a single set of genetic information; describing a cell with one chromosome of each type.Hapten:（半抗原） A small molecule which, when linked to a larger molecule, elicits an immune response.Haworth perspective formulas:（Haworth透视式） A method for representing cyclic chemical structures so as to define the configuration of each substituent group; the method commonly used for representing sugars.Helicase(解螺旋酶) An enzyme that, catalyzes the separation of strands in a DNA molecule before replication.Heme:（血红素） The iron-porphyrin prosthetic group of heme proteins.Heme protein:（血红素蛋白） A protein containing a heme as a prosthetic group.Hemoglobin:（血红蛋白） A heme protein in erythrocytes; functions in oxygen transport.Henderson-Haelbalch equation: An equation relating the pH, the pKa, and the ratio of the concentrations of the proton-acceptor (A+) and proton-donor (HA) species in a solution.Hepatocyte( 肝细胞) The major cell type of liver tiue.Heteroduplex DNA(异源双链DNA) Duplex DNA containing complementary strands derived from two different DNA molecules with similar sequences, often as a product of genetic recombination.Heteropolysaccharide:（杂多糖） A polysaccharide containing more than one type of sugar.Heterotroph:（异养生物） An organism that requires complex nutrient molecules, such as glucose, as a source of energy and carbon.Heterotropic:（异促的） Describes an allosteric modulator that is distinct from the normal ligand.Heterotropic enzyme: （异促酶）An allosteric enzyme requiring a modulator other than its substrate.Hexose:（己糖） A simple sugar with a backbone containing six carbon atoms.High-energy compound: （高能化合物）A compound that on hydrolysis undergoes a large decrease in free energy under standard conditions.High-performance liquid chromatography (HPLC)：（高效液相色谱） Chromatographic procedure, often conducted at relatively high preures, using automated equipment that permits refined and highly reproducible profiles, Hill reaction:（希尔反应） The evolution of oxygen and the photoreduction of an artificial electron acceptor by a chloroplast preparation in the absence of carbon dioxide.Histones:（组蛋白） The family of five basic proteins that aociate tightly with DNA in the chromosomes of all eukaryotic cells, 8 1

Holliday intermediate（赫利地中间物） An intermediate in genetic recombination in which two double-stranded DNA molecules are joined by virtue of a reciprocal croover involving one strand of each molecule.Holoenzyme:（全酶） A catalytically active enzyme including all neceary subunits, prosthetic groups, and cofactors.Homeobox:（同源框） A conserved DNA sequence of 180 base pairs encoding a protein domain found in many proteins that play a regulatory role in development.Homeodomain:（ 发育同源结构域） The protein domain encoded by the homeobox.Homeostasis:（内稳态） The maintenance of a dynamic steady state by regulatory mechanisms that compensate for changes in external circumstances.Homeotic genes:（同源框基因）Genes that regulate the development of the pattern of segments in the Drosophila body plan; similar genes are found in most vertebrates.Homologous genetic recombination:（同源遗传重组） Recombination between two DNA molecules of similar sequence, occurring in all cells; occurs during meiosis and mitosis in eukaryotes.Homologous proteins:（同源蛋白） Proteins having sequences and functions similar in different species; for example, the hemoglobins.Homopolysaccharide: （同多糖）A polysaccharide made up of only one type of monosaccharide unit.Homotropic:(同促的） Describes an allosteric modulator that is identical to the normal ligand.Homotropic enzyme:（同促酶） An allosteric enzyme that uses its substrate as a modulator.Hormone:（激素） A chemical substance synthesized in small amounts by an endocrine tiue and carried in the blood to another tiue, where it acts as a meenger to regulate the function of the target tiue or organ.Hormone receptor:(激素受体) A protein in, or on the surface of, target cells that binds a specific hormone and initiates the cellular response, Hormone response element (HRE):（激素响应元件） A short (12 to 20 bp) DNA sequence to which receptors for steroid, retinoid, thyroid, and vitamin D hormones bind, altering the expreion of the contiguous genes.For each hormone, there is a consensus sequence preferred by the cognate receptor.Hyaluronic acid:（透明质酸） A high molecular weight, acidic polysaccharide typically composed of the alternating disaccharide GlcUA(β1→3)GlcNAc, Hyaluronic acid is a major component of the extracellular matrix, and forms larger complexes (proteoglycans) with proteins and other acidic polysaccharides.Hydrogen bond:（氢键）A weak electrostatic attraction between one electronegative atom (such as oxygen or nitrogen) and a hydrogen atom covalently linked to a second electronegative atom. 9 1

Hydrolases:（水解酶） Enzymes (proteases, lipases, phosphatases, nucleases, for example) that catalyze hydrolysis reactions.Hydrolysis:（水解） Cleavage of a bond, such as an anhydride or peptide bond, by the addition of the elements of water, yielding two or more products, Hydronium ion: （水合氢离子）The hydrated hydrogen ion (H3O+).Hydropathy index:（亲水指数） A scale that exprees the relative hydrophobia and hydrophilic tendencies of a chemical group.Hydrophilic：（亲水的） Polar or charged; describing molecules or groups that aociate with (diolve easily in) water.Hydrophobic:（疏水的） Nonpolar; describing molecules or groups that are insoluble in water.hydrophobic interactions （疏水相互作用） The aociation of nonpolar groups, or compounds, with each other in aqueous systems, driven by the tendency of the surrounding water molecules to seek their most stable(disordered)state.Hyperchromic effect(增色效应) The large increase in light absorption at 260 nm occurring as a double- helical DNA is melted (unwound).Hypoxia:（低氧） The metabolic condition in which the supply of oxygen is severely limited.I Immune response:（免疫反应） The capacity of a vertebrate to generate antibodies to an antigen, a macromolecule foreign to the organism.Immunoglobulin(免疫球蛋白) An antibody protein generated against, and capable of binding specifically to an antigen.in vitro:（体外） \"In gla\"; that is, in the test tube.in vivo:（体内） \"In life\"; that is, in the living cell or organism.Induced fit: （诱导契合）A change in the conformation of an enzyme in response to substrate binding that renders the enzyme catalytically active; also used to denote changes in the conformation of any macromolecule in response to ligand binding such that the binding site of the macromolecule better conforms to the shape of the ligand.Indncer:（诱导物） A signal molecule that, when bound to a regulatory protein, produces an increase in the expreion of a given gene.Induction:（诱导） An increase in the expreion of a gene in response to a change in the activity of a regulatory protein.Informational macromolecules:（信息大分子） Biomolecules containing information in the form of specific sequences of different monomers; for example, many proteins, lipids, polysaccharides, and nucleic acids.Initiation codon（起始密码） AUG (sometimes GUG in prokaryotes); codes for the first amino acid in a polypeptide sequence: N-formylmethionine in prokaryotes, and methionine in eukaryotes. 0

2 Initiation complex:（ 起始复合物） A complex of a ribosome with an mRNA and the initiating Met-tRNAMet or fMet-tRNAMet, ready for the elongation steps.Inorganic pyrophosphatase(无机焦磷酸酶) An enzyme that hydrolyzes a molecule of inorganic pyrophosphate to yield two molecules of (ortho) phosphate; also known as pyrophosphatase.Insertion mutation:（插入突变） A mutation caused by insertion of one or more extra bases, or a mutagen, between succeive bases in DNA.Insertion sequence:（插入序列） Specific base sequences at either end of a transposable segment of DNA.Integral proteins:（膜整体蛋白） Proteins firmly bound to a membrane by hydrophobic interactions; as distinct from peripheral proteins.Integrin:（ 整连蛋白） One of a large family of heterodimeric transmembrane proteins that mediate adhesion of cells to other cells or to the extracellular matrix.Intercalating mutagen:（嵌入突变） A mutagen that inserts itself between succeive bases in a nucleic acid, causing a frame-shift mutation.Intercalation: （嵌入）Insertion between stacked aromatic or planar rings; for example, the insertion of a planar molecule between two succeive bases in a nucleic acid.Iinterferons:（干扰素） A cla of glycoproteins with antiviral activities.Intermediary metabolism:（中间代谢） In cells, the enzyme-catalyzed reactions that extract chemical energy from nutrient molecules and utilize it to synthesize and aemble cell components.Intron (intervening sequence)（内含子，间隔序列） A sequence of nucleotides in a.gene that is transcribed but excised before the gene is translated.Ion channel:（离子通道） An integral protein that provides for the regulated transport of a specific ion, or ions, acro a membrane.Ion-exchange resin:（离子交换树脂） A polymeric resin that contains fixed charged groups; used in chromatographic columns to separate ionic compounds.Ion product of water (Kw)（水的离子积） The product of the concentrations of H+and OH- in pure water: kw = [H+] X [OH- ] = 10-14 at 25 °C.Ionizing radiation（电离辐射） A type of radiation, such as x rays, that causes lo of electrons from some organic molecules, thus making them more reactive.Ionophore:（离子载体） A compound that binds one or more metal ions and is capable of diffusing acro a membrane, carrying the bound ion.Iron-sulfur center:（铁硫中心） A prosthetic group of certain redox proteins involved in electron transfers; Fe2+ or Fe3+ is bound to inorganic sulfur and to Cys groups in the protein.Isoelectric focusing（等电聚焦） An electrophoretic method for separating macromolccules on the basis of their isoelectric pH. 1 2

Isoelectric pH (isoelectric point)( 等电点) The pH at which a solute has no net electric charge and thus does not move in an electric field, Isoenzymes:（同工酶） See isozymes.Isomerases:（异构酶类） Enzymes that catalyze the transformation of compounds into their positional isomers.Isomers: （异构体）Any two molecules with the same molecular formula, but a different arrangement of molecular groups.Isoprene:（异戊二烯） The hydrocarbon 2-methyl-1, 3-butadiene, a recurring structural unit of the terpenoid biomolecules.Isoprenoid: （类异戊二烯）Any of a large number of natural products synthesized by enzymatic polymerization of two or more isoprene units; also called terpenoids.Isothermal: （等温的）Occurring at constant temperature.Isotopes:（同位素） Stable or radioactive forms of an element that differ in atomic weight but are otherwise chemically identical to the naturally abundant form of the clement; used as tracers.Isozymes:（同工酶） Multiple forms of an enzyme that catalyze the same reaction but differ from each other in their amino acid sequence, substrate affinity, Vm, and / or regulatory properties; also called isoenzymes.K Keratins;( 角蛋白) Insoluble protective or structural proteins consisting of parallel polypeptide chains in α-helical or β conformations.Ketogenic amino acids（生酮氨基酸） Amino acids with carbon skeletons that can serve as precursors of the ketone bodies.Ketone bodies:（酮体） Acetoacetate, D-β-hydroxybutyrate, and acetone; water-soluble fuels normally exported by the liver but overproduced during fasting or in untreated diabetes mellitus.Ketose:（酮糖） A simple monosaccharide in which the carbonyl group is a ketone.Ketosis:（酮尿症） A condition in which the concentration of ketone bodies in the blood, tiues, and urine is abnormally high.Kinases:（激酶） Enzymes that catalyze the phosphorylation of certain molecules by ATP.Kinetics: （动力学）The study of reaction rates.Krebs cycle: （Krebs 循环）See citric acid cycle.L Lagging strand（滞后链） The DNA strand that, during replication, must be synthesized in the direction opposite to that in which the replication fork moves.Law of ma action:（质量作用定律） The law stating that the rate of any given chemical reaction is proportional to the product of the activities (or concentrations) of the reactants. 2 2

Leader:（ 前导序列） A short sequence near the amino terminus of a protein or the 5\' end of an RNA that has a specialized targeting or regulatory function.Leading strand:（领头链） The DNA strand that, during replication, is synthesized in the same direction in which the replication fork moves.Leaky mutant:（渗漏突变） A mutant gene that gives rise to a product with a detectable level of biological activity, Leaving group:（离去基团） The departing or displaced molecular group in a unimolecular elimination or a bimolecular substitution reaction.Lectin（凝集素） A protein that binds a carbohydrate, commonly an oligosaccharide, with very high affinity and specificity, mediating cell-cell interactions.Lethal mutation:（致死突变） A mutation that inactivates a biological function eential to the life of the cell or organism.Leucine zipper:（亮氨酸拉链） A protein structural motif involved in protein-protein interactions in many eukaryotic regulatory proteins; consists of two interacting a helices in which Leu residues in every seventh position are a prominent, feature of the interacting surfaces.Leukotrienes:（白三烯） A family of molecules derived from arachidonate; muscle contractants that constrict air paages in the lungs and are involved in asthma.Levorotatory isomer:（左旋异构体） A stercoisomer that rotates the plane of plane-polarized light counterclockwise.Ligand: A small molecule that binds specifically to a larger one; for example, a hormone is the ligand for its specific protein receptor.Ligases:（连接酶） Enzymes that.catalyze condensation reactions in which two atoms are joined using the energy of ATP or another energy-rich compound.Light-dependent reactions:（光反应） The reactions of photosynthesis that require light and cannot, occur in the dark; also known as the light reactions.Lineweaver-Burk equation: An algebraic transform of the Michaells-Menten equation, allowing determination of Vmax and Km by extrapolation of [S] to infinity.Linking number: (连接数)The number of times one closed circular DNA strand is wound about another; the number of topological links holding the circles together.Lipases:（脂酶） Enzymes that catalyze the hydrolysis of triacylglycerols.Lipid:（脂） A small water-insoluble biomolecule generally containing fatty acids, st.erols, or isoprenoid compounds.Lipoate (lipoic acid)（硫辛酸） A vitamin for some microorganisms; an intermediate carrier of hydrogen atoms and acyi groups hi a-keto acid dehydrogenases.Lipoprotein（脂蛋白） A lipid-protein aggregate that serves to carry water-insoluble lipids in the blood.The protein component alone is an apolipoprotein.Liposome:（脂质体） A small, spherical vesicle composed of a phospholipid bilayer, which forms spontaneously when phospholipids are suspended in an aqueous buffer. 3 2

Low-energy phosphate compound:（低能化合物） A phosphorylated compound with a relatively small standard free energy of hydrolysis.Lyases:（裂解裂合酶类） Enzymes that catalyze the removal of a group from a molecule to form a double bond, or the addition of a group to a double bond.Lymphocytes:（淋巴细胞） A subcla of leukocytes involved in the immune response.B lymphocytes synthesize and secrete antibodies; T lymphocytes either play a regulatory role in immunity or kill foreign and virus-infected cells.Lysis:（裂解） Destruction of a cell\'s plasma membrane or of a bacterial cell wall, releasing the cellular contents and killing the cell.Lysosome:（溶酶体） A membrane-bounded organelle in the cytoplasm of eukaryotic cells; it contains many hydrolytic enzymes and serves as a degrading and recycling center for unneeded components.M Macromolecule:（大分子） A molecule having a molecular weight in the range of a few thousand to many millions.Matrix:（基质） The aqueous contents of a cell or organelle (the mitochondrion, for example) with diolved solutes.Meiosis:（减数分裂） A type of cell division in which diploid cells give rise to haploid cells destined to become gametes.Membrane potential (Vm):（膜电位） The difference in electrical potential acro a biological membrane, commonly measured by the insertion of a microelectrode.Typical membrane potentials vary from —25 mV (by convention, the negative sign indicates that the inside is negative relative to the outside) to greater than —100 mV acro some plant vacuole membranes.Membrane transport:（膜转运） Movement of a polar solute acro a membrane via a specific membrane protein (a transporter).Meenger RNA (mRNA):（信使RNA） A cla of RNA molecules, each of which is complementary to one strand of DNA; carries the genetic meage from the chromosome to the ribosomes, Metabolism(新陈代谢) The entire set of enzyme-catalyzed transformations of organic molecules in living cells; the sum of anabolism and catabolism.Metabolite:（代谢物） A chemical intermediate in the enzyme-catalyzed reactions of metabolism.Metalloprotein:（金属蛋白） A protein having a metal ion as its prosthetic group.Metamerism:（分节） Division of the body into segments; in insects, for example.Micelle:（微团） An aggregate of amphipathic molecules in water, with the nonpolar portions in the interior and the polar portions at the exterior surface, exposed to water.Michaelis constant (Km)（米氏常数） The substrate concentration at which an enzyme-catalyzed reaction proceeds at one-Iialf its maximum velocity. 4 2

Michaelis-Menten equation（米氏方程） The equation describing the hyperbolic dependence of the initial reaction velocity, V, on substrate concentration, [S], in many enzyme-catalyzed reactions.Michaelis-Menten kinetics: （米氏动力学）A kinetic pattern in which the initial rate of an enzyme-catalyzed reaction exhibits a hyperbolic dependence on substrate concentration.Microbodies:（微体） Cytoplasmic, membrane-bounded vesicles containing peroxide-forming and peroxide-destroying enzymes; include lysosomes, peroxisomes, and glyoxysomes.Microfilaments:（微丝） Thin filaments composed of actin, found in the cytoplasm of eukaryotic cells; serve in structure and movement.Microtubules:（微管） Thin tubules aembled from two types of globular tubulin subunits; present, in cilia, flagella, centrosomes, and other contractile or motile structures.Mismatch(碱基错配) a base pair in a nucleic acid that cannot form normal Watson-Crick pairs.Mismatch repair: (错配修复) an enzymatic system for repairing base mismatches in DNA.Mitochondrion:（线粒体） Membrane-bounded organelle in the cytoplasm of eukaryotes; contains the enzyme systems required for the citric acid cycle, fatty acid oxidation, electron transfer, and oxidative phosphorylation.Mitosis:（有丝分裂） The multistep proce in eukaryotic cells that results in the replication of chromosomes and cell division, Mixed-function oxidases:（混合功能氧化酶） Enzymes (a inonooxygenase, for example) that catalyze reactions in which two reductants, one of which is generally NADPH, the other the substrate, are oxidized.One oxygen atom is incorporated into the product, the other is reduced to H^O.These enzymes often employ cylochrome P-450 to cany electrons from NADPH to 0^.Mixed inhibition:（混合抑制） The reversible inhibition pattern resulting when an inhibitor molecule can bind to either the free enzyme or to the enzyme-substrate complex (not necearily with the same affinity).Modulator:（调节物） A Metabolite that, when bound to the allosteric site of an enzyme, alters its kinetic characteristics.Molar solution: （摩尔溶液）One mole of solute diolved in water to give a total volume of 1000 mL.Mole: （摩尔）One gram molecular weight of a compound.See Avogadro\'s number.Monoclonal antibodies:（单克隆抗体） Antibodies produced by a cloned hybridoma cell, which therefore are identical and directed against the same epitope of the antigen.Monolayer:（单分子层） A single layer of oriented lipid molecules.Monoprotic acid: An acid having only one diociable proton- 5 2

Monosaccharide:（单糖） A carbohydrate consisting of I single sugar unit.mRNA: See meenger RNA.Mucopolysaccharide:（粘多糖） An older name for a glycosaminoglycan.Multienzyme system:（多酶系统） A group of related enzyme; participating in a given metabolic pathway.Mutarotation:（变旋现象） The change in specific rotation o a pyranose or furanose sugar or glycoside accompanying tlie equilibration of its a- and j8- anomcric forms.Mutases（变位酶）: Enzymes that catalyze the transposition of functional groups.Mutation: An inheritable change in the nucleotide sequence of a chromosome.Myofibril: （肌原纤维）A unit of thick and thin filaments of muscle fibers.Myosin:（肌球蛋白） A contractile protein; the major component of the thick filaments of muscle and other actin-myosin systems.N NAD, NADP (nicotinamide adenine dinucleotide, nicotinamide adenine dinucleotide phosphate): Nicotinaniide-containing coenzyme: functioning as carriers of hydrogen atoms and electrons in some oxidation-reduction reactions.Native conformation:（天然构象） Ttie biologically active conformation of a macromolecule.Negative cooperativity:（负协同性） A phenomenon of some inultisubunit enzymes or proteins in which binding of a ligand or substrate to one subunit impairs binding to another subunit.Negative feedback:（负反馈） Regulation of a biochemical pathway achieved when a reaction product.inhibits an earlier step in the pathway.Neuron:（神经元） A cell of nervous tiue specialized for transmiion of a nerve impulse.Neurotransmitter: （神经递质）A low molecular weight compound (usually containing nitrogen) secreted from the terminal of a neuron and bound by a specific receptor in the next neuron; serves to transmit a nerve impulse.Nicotinamide adenine dinucleotide, nicotinamide adenine dinucleotide phosphate: See NAD,NADP.Ninhydrin reaction（茚三酮反应） A color reaction given by amino acida and peptides on heating with ninhydrin; widely used for their detection and estimation.Nitrogen cycle:（氮循环） The cycling of various forms of biologically available nitrogen through the plant, animal, and microbial worlds, and through the atmosphere and geosphere.Nitrogen fixation: （固氮作用）Conversion of atmospheric nitrogen (N3) into a reduced, biologically available form by nitrogen-fixing organisms.Nitrogenase complex: （固氮复合物）A system of enzymes capable of reducing atmospheric nitrogen to ammonia in the presence of ATP. 6 2

Noncyclic electron flow:（非环式电子流） The light-induced tlow of electrons from water to NADP^ in oxygen-evolving photosynthesis; it involves both photosystems I and II.Noneential amino acids:（非必需氨基酸） Amino acids tliat can be made by humans and other vertebrates from simpler precursors, and are thus not required in the diet.Nonheme iron proteins:（非血红素铁蛋白） Proteins, usually acting in oxidation-reduction reactions, containing iron but no porphyrin groups.Nonpolar:（非极性的） Hydrophobic; describing molecules or groups that are poorly soluble in water.Nonsense codon:（无义密码） A codon that docs not specify an amino acid, but signals the termination of a polypeptide chain.Nonsense mutation: （无义突变） A mutation that results in the premature termination of a polypeptide chain.Nonsense suppreor（无义抑制） A mutation, usually in the gene for a tRNA, that, causes an amino acid to be inserted into a polypeptide in response to a termination codon.Nuclear magnetic resonance (NMR) spectroscopy（核磁共振谱） A technique that utilizes certain quantum mechanical properties of atomic nuclei to study the structure and dynamics of the molecules of which they are a part.Nucleases:（核酸酶） Knzymes that hydrolyze the internucicotidc (phosphodiester) linkages of nucleic acids.Nucleic acids:（核酸） Biologically occurring polynucleotides in which the nucleotide residues are linked in a specific sequence by phosphodiester bonds; DNA and RNA.Nucleoid: （拟核）In bacteria, the nuclear zone that contains the chromosome but has no surrounding membranc- Nucleolus:（核仁） A densely staining structure in the nucleus of eukaryotic cells; involved in rRNA synthesis and ribosome formation.Nucleophile:（亲核剂） An electron-rich group with a strong tendency to donate electrons tu an electron-deficient nucleus (electrophilc); the entering reactant in a bimolecular substitution reaction.Nucleoplasm: （核质）The portion of a cell\'s contents enclosed by the nuclear membrane; also called the nuclear matrix.Nucleoside:（核苷） A compound consisting of a purinc or pyrimidine base cuvalently linked to a pentose.Nucleoside diphosphate kinase: （核苷二磷酸激酶）An enzyme that catalyzes the transfer of the terminal phosphate of a nucleoside 5\'-triphosphate to a nucleoside 5\'-diphosphate. 7 2

Nucleoside diphosphate sugar: （核苷二磷酸糖）A coenzymelike carrier of a sugar molecule, functioning in the enzymatic synthesis of polysaccharides and sugar derivatives.Nucleoside monophosphate kinase: （核苷一磷酸激酶）An enzyme that catalyzes the transfer of the termi- nal phosphate of ATP to a nucleoside 5\'-monophosphate.Nucleosome:（核小体） Structural unit for packaging chromatin; consists of a UNA strand wound around a histone core.Nucleotide: （核苷酸）A nucleoside phosphorylated at one of its pentose hydroxyl groups.Nucleus:（细胞核） In cukaryotes, a membrane-bounded organellc that contains chromosomes.O Oligomer:(寡聚体) A short polymer, usually of amino acids, sugars, or nucleotides; the definition of \"short\" is somewhat arbitrary, but usually le than 50 subunits.Oligomeric protein: (寡聚蛋白) A multisubunit protein having two or more identical polypeptide chains.Oligonucleotide（寡核苷酸）: A short polymer of nucleotides (usually le than 50).Oligopeptide: （寡肽）A few amino acids joined by peptide bonds.Oligosaccharide:（寡糖） Several monosaccharide groups joined by glycosidic bonds.Oncogene:（致癌基因） A cancer-causing gene; any of several mutant genes that, cause cells to exhibit, rapid, uncontrolled proliferation.See also proto- oncogene.Open reading frame:（开放阅读框） A group of contiguous nonoverlapping nucleotide codons in a DNA or RNA molecule that do not include a termination codon.Open system:（开放系统） A system that exchanges matter and energy with its surroundings.See also system.Operator(操纵基因) A region of DNA that interacts with a repreer protein to control the expreion of a gene or group of genes.Operon:（操纵子） A unit, of genetic expreion consisting of one or more related genes and the operator and promoter sequences that regulate their transcription.optical activity:（光学活性） The capacity of a substance to rotate the plane of plane-polarized light.Optimum pH:（最适pH）The characteristic pH at which an enzyme has maximal catalytic activity.Organelles(细胞器) Membrane-bounded structures found in eukaryotic cells; contain enzymes and other components required for specialized cell functions.Origin:（起始位点） The nucleotide sequence or site in DNA where DNA replication is 8 2

initiated.Osmosis;（渗透作用） Bulk flow of water through a semi-permeable membrane into another aqueous compartment containing solute at a higher concentration.Osmotic preure（渗透压）: Preure generated by the osmotic flow of water through a semipermeable membrane into an aqueous compartment containing solute at a higher concentration.Oxidases:（氧化酶） Enzymes that catalyse oxidation reactions in which molecular oxygen serves as the electron acceptor, but neither of the oxygen atoms is incorporated into the product.Compare oxygenases.

Oxidation:（氧化作用） The lo of electrons from a compound.Oxidation-reduction reaction: （氧化还原反应）A reaction in which electrons are transferred from a donor to an acceptor molecule; also called a redox reaction.Oxidative phosphorylation（氧化磷酸化） The enzymatic phosphorylation of ADP to ATP coupled to electron transfer from a substrate to molecular oxygen.Oxidizing agent (oxidant)（氧化剂） The acceptor of electrons in an oxidation-reduction reaction.

Oxygen debt: （氧债）The extra oxygen (above the normal resting level) consumed in the recovery period after strenuous physical exertion.Oxygenases:（加氧酶） Enzymes that catalyze reactions in which oxygen atoms are directly incorporated into tile product, forming a hydroxyl or carboxyl group.In reactions catalyzed by a monooxygenase, only one of the two 0 atoms is incorporated; the other is reduced to rLO; in reactions catalyzed by a dioxygenase, both 0 atoms are incorporated into the product.Compare oxidases.P

Palindrome（回文结构）: A segment of duplex DNA in which the base sequences of the two strands exhibit twofold rotational symmetry about an axis.Partition coefficient（分配系数）: A constant that exprees the ratio in which a given solute will be partitioned or distributed between two given immiscible liquids at equilibrium.Pathogenic:（病原性的） Disease-causing.Pentose:（戊糖） A simple sugar with a backbone containing five carbon atoms.Pentose phosphate pathway（磷酸戊糖途径）: A pathway that serves to interconvert hexoses and pentoses and is a source of reducing equivalents and pentoses for biosynthetic procees; present, in most organisms.Also called the phosphogluconate pathway.Peptidases:（肽酶） Enzymes that hydrolyze peptide bonds.Peptide:（肽） Two or more ammo acids covaleiitly joined by peptide bonds.Peptide bond（肽键） A substituted amide linkage between the a-amino group of one amino acid and the a-carboxyl group of another, with the elimination of the elements of 9 2

water, Peptide mapping:（肽指纹图） The characteristic two-dimensional pattern (on paper or gel) formed by the separation of a mixture of peptides resulting from partial hydrolysis of a protein; also known as peptide fingerprinting.Peptidoglycan:（肽聚糖） A major component of bacterial cell walls; generally consists of parallel heteropolysaccharides cro-linked by short peptides.Peripheral proteins:（外周蛋白） Proteins that are loosely or reversibly bound to a membrane by hydrogen bonds or electrostatic forces; generally water-soluble once released from the membrane.Permeases:（透过酶） See transporters.Peroxisome:（过氧化物酶体） Membrane-bounded organelle in the cytoplasm of cukaryotic cells; contains peroxide-forming and peroxide-destroying enzymes.pH: The negative logarithm of the hydrogen ion concentration of an aqueous solution.Phage: See bacteriophage.Phenotype:（表型） The observable characteristics of an organism.Phosphatases:（磷酸酶） Enzymes that hydrolyze a phosphate ester or anhydride, releasing inorganic phosphate, Pi.Phosphodiester linkage:（磷酸二酯键） A chemical grouping that contains two alcohols esterified to one molecule of phosphoric acid, winch thus serves as a bridge between them.Phosphogluconate pathway:（磷酸己糖途径） An oxidative pathway beginning with glucose 6-phosphate and leading, via 6-phosphogluconate, to pentose phosphates and yielding NADPH.Also called the pentose phosphate pathway.Phospholipid:（磷脂） A lipid containing one or more phosphate groups.Phosphorolysis:（磷酸解） Cleavage of a compound with phosphate as the attacking group; analogous to hydrolysis.Phosphorylases; Enzymes that catalyze phosphorolysis (defined above).Phosphorylation（磷酸化作用） Formation of a phosphate derivative of a biomolecule, usually by enzymatic transfer of a phosphoryl group from ATP.Phosphorylation potential (ΔGp)（磷酸化能力）: The actual free-energy change of ATP hydrolysis under the nonstandard conditions prevailing within a cell.Photochemical reaction center（光化学反应中心） The part of a photosynthetic complex where the energy of an absorbed photon causes charge separation, initiating electron transfer.Photon: （光子）The ultimate unit (a quantum) of light energy.Photophosphorylation（光合磷酸化） The enzymatic formation of ATP from ADP coupled to the light-dependent transfer of electrons in photosynthetic cells.Photoreduction（光还原） The light-induced reduction of an electron acceptor in phot.osynthetic cells. 0

3 Photorespiration（光呼吸） Oxygen consumption occurring in illuminated temperate-zone plants, largely due to oxidation ofphosphoglycolate.Photosynthesis（光合作用） The use of light energy to produce carbohydrates from carbon dioxide and a reducing agent sucli as water.Photosynthetic phosphorylation（光合磷酸化） See photophosphorylation .Photosystem（光系统） In photosynthetic cells, a functional set of light-absorbing pigments and its reaction center.Phototroph（光能生物） An organism that.can use the energy of light to synthesize its own fuels from simple molecules such as carbon dioxide, oxygen, and water; as distinct from a chemotroph.pKa: The negative logarithm of an equilibrium constant.Plasma membrane(质膜) The exterior membrane surrounding the cytoplasm of a cell.Plasma proteins（血浆蛋白） The proteins present in blood plasma.Plasmalogen A phospholipid with an alkenyl ether substituent on the C-l of glyccrol.Plasmid（质粒） An extrachromosomal, independently replicating, small circular DNA molecule; commonly employed in genetic engineering.Plastid（质体） In plants, a self-replicating organelle; may differentiate into a chloroplast.Platelets（血小板） Small, enucleated cells that initiate blood clotting; they arise from cells called megakaryocytes in the bone marrow.Also known as thrombocytes.Pleated sheet（折叠片） The side-by-side, hydrogen-bonded arrangement of polypeptide chains in the extended 0 conformation.Plectonemic: A structure in a molecular polymer in which there is a net twisting of strands about each other in some simple and regular way.Polar（极性的) Hydrophilic, or \"water-loving\"; describing molecules or groups that are soluble in water.Polarity:（极性） (1) In chemistry, the nonuniform distribution of electrons in a molecule; polar molecules are usually soluble in water.(2) In molecular biology, the distinction between the 5\' and 3\' ends of nucleic acids.Poly(A) tail: A length of adenosine residues added to the 3\' ends of many mRNAs in eukaryotes (and sometimes in bacteria).Polycistronic mRNA（多顺反子mRNA） A contiguous mRNA with more than two genes that can be translated into proteins.Polyclonal antibodies(多克隆抗体) A heterogeneous pool of antibodies produced in an animal by a number of different.B lymphocytes in response to an antigen.Different antibodies in the pool recognize different parts of the antigen.Polylinker（多连接物）A short, often synthetic, fragment of DNA containing recognition sequences for several restriction endomicleases. 1 3

Polymerase chain reaction (PCR)（聚合酶链式反应） A repetitive procedure that results in a geometric amplification of a specific DNA sequence.Polymorphic（多态性的） Describing a protein for which amino acid sequence variants exist in a population of organisms, but the variations do not destroy the protein\'s function.Polynucleotide（多核苷酸） A covalently linked sequence of nucieotides in which the 3\' hydroxyl of the pentose of one nucleotide residue is joined by a phosphodiester bond to the 5\' hydroxyl of the pentose of the next residue.Polypeptide（多肽） A long chain of amino acids linked by pcptide bonds; the molecular weight, is generally le than 10,000.Polyribosome（多核糖体） See polysome.Polysaccharide（多糖） A linear or branched polymer of monosaccharide units linked by glycosidic bonds.Polysome (polyribosome): A complex of an inRNA molecule and two or more ribosomes.P/0 ratio（磷/氧比） The number of moles of ATP formed in oxidative phosphorylation per gO^ reduced (thus, per pair of electrons paed to Oa).Experimental values used in this text are 2.5 for paage of electrons from NADH to (X, and 1.5 for paage of electrons from FADH to 0^, Some textbooks use the integral values of 3.0 and 2.0.Porphyria（卟啉症）Genetic condition resulting from the lack of one or more enzymes required to synthesize porphyrins.Porphyrin: （卟啉） Complex nitrogenous compound containing four substituted pyrroles covalently joined into a ring; often complexed with a central metal atom.Positive cooperativity（正协同性） A phenomenon of some multisubunit enzymes or proteins in which binding of a ligand or substrate to one subunit.facilitates binding to another subunit.Posttranscriptional proceing（转录后加工） The enzymatic proceing of the primary RNA transcript, producing functional mRNA, tRNA, and/or rRNA molecules.Posttranslational modification（翻译后修饰） Enzymatic proceing of a polypeptide chain after translation from its mRNA.Primary structure（一级结构） A description of the covalent backbone of a polymer (macromolecule), including the sequence of monomeric subunits and any interchain and intrachain covalent bonds.Primary transcript（原初转录本） The immediate RNA product of transcription before any posttranscriptional proceing reactions.Primase（引物酶）: An enzyme that catalyzes the formation of RNA oligonucleotides used as primers by DNA polymerascs.Primer（引物）A short oligomer (of sugars or nucieotides, for example) to which an enzyme adds additional monomeric subunits. 2 3

Primer terminus（引物末端） The end of the primer to which monomeric suhunits are added.Primosome（引发体）An enzyme complex that synthesizes the primers required for lagging strand DNA synthesis.Probe（探针）A labeled fragment of nucleic acid containing a nucleotide sequence complementary to a gene or genomic sequence that one wishes to detect in a hybridization experiment, Proceivity（持续合成能力）For any enzyme tliat catalyzes the synthesis of a biological polymer, the property of adding multiple subunits to the polymer without diociating from the substrate.Prochiral molecule（原手性化合物） A symmetric molecule that can react asymmetrically with an enzyme having an asymmetric active site, generating a chiral product.Projection formulas（透视式）A method for representing molecules to show the configuration of groups around chiral centers; also known as Fischer projection formulas.Prokaryote（原核生物） A bacterium; a unicellular organism with a single chromosome, no nuclear envelope, and no membrane-bounded organelles.Promoter（启动子） A DNA sequence at.which RNA polymerase may bind, leading to initiation of transcription.Proofreading（校对） The correction of errors in the synthesis of an information-containing biopolymer by removing incorrect monomeric subunits after they have been covalent.ly added to the growing polymer.Prostaglandins（前列腺素） A cla of lipid-soluble, hormonelike regulatory molecules derived from arachidonate and other polyunsaturated fatty acids.Prosthetic group（辅基） A metal ion or an organic compound (other than an amino acid) that is covalently bound to a protein and is eential to its activity.Proteasome（蛋白酶体）Supramolecular aembly of enzymatic complexes that.function in the degradation of damaged or unneeded cellular proteins.Protein（蛋白质）A macromolecule composed of one or more polypeptide chains, each with a characteristic sequence of amino acids linked by peptide bonds, Protein kinases（蛋白激酶） Enzymes that transfer the terminal phosphoryl group of ATP or another nucleoside tnphosphate to a Ser, Thr, Tyr, Asp, or His side chain in a target protein, thereby regulating the activity or other properties of that protein.Protein targeting（蛋白质分送）The proce by which newly synthesized proteins are sorted and transported to their proper locations in the cell.Proteoglycan（蛋白聚糖）A hybrid macromolecule consisting of a heteropolysaccharidc joined to a polypeptide; the polysaccharide is the major component. 3 3

Proto-oncogene（原癌基因） A cellular gene, usually encoding a regulatory protein, that can be converted into an oncogene by mutation.Proton acceptor（质子受体） An anionic compound capable of accepting a proton from a proton donor; that is, a base.Proton donor（质子供体）The donor of a proton in an acid-base reaction; that is, an acid.Proton-motive force（质子推动力）The electrochemical potential inherent in a transmcmbrane gradient of H\'1\' concentration; used in oxidative phosphorylation and photophosphorylation to drive ATF synthesis.Protoplasm（原生质）A general term referring to the entire contents of a living cell.Purine（嘌呤）A nitrogenous heterocyclic base found in nucleotides and nucleic acids; containing fused pyrimidine and imidazole rings.Puromycin（嘌呤霉素）An antibiotic that inhibits polypeptide synthesis by being incorporated into a growing polypeptide chain, causing its premature termination.Pyranose（吡喃糖）A simple sugar containing the six-membered pyran ring.Pyridine nucleotide（嘧啶核苷酸）A nucleotide coenzyme containing the pyridine derivative nicotinamide; NAD or NADP.Pyridoxal phosphate（磷酸吡哆醛） A coenzyme containing the vitamin pyridoxine (vitamin B(;) ; functions in reactions involving amino group transfer.Pyrimidine（嘧啶）A nitrogenous heterocyclic base found in nucleotides and nucleic acids.Pyrimidine dimer（嘧啶二聚体） A covalently joined dimer of two adjacent pyrimidine residues in DNA, induced by absorption of LIV light; most commonly derived from two adjacent thymines (a thymine dimer).Pyrophosphatase（焦磷酸酶） See inorganic pyrophosphatase.Q Quantum（量子） The ultimate unit of energy.Quaternary structure（四级结构）The three-dimensional structure of a multisubunit protein; particularly the manner in which the subunits fit together.R R group: (1) Formally, an abbreviation denoting any alkyi group.(2) Occasionally, used in a more general sense to denote virtually any organic substituent (the R groups of amino acids, for example).Racemic mixture (racemate)（外消旋化合物） An equimolar mixture of the u and L stereoisomers of an optically active compound.Radical（自由基） An atom or group of atoms poeing an unpaired electron; also called a free radical.Radioactive isotope（放射性同位素）An isotopic form of an element with an unstable nucleus that stabilizes itself by emitting ionizing radiation. 4 3

Radioimmunoaay（放射免疫实验）A sensitive and quantitative method for detecting trace amounts of a biomolecule, based on its capacity to displace a radioactive form of the molecule from combination with its specific antibody.Rate constant（速度常数）The proportionality constant that relates the velocity of a chemical reaction to the concentration(s) of the reactant(s).Rate-limiting step（限速步骤） (1) Generally, the step in an enzymatic reaction with the greatest activation energy or the transition state of highest free energy.(2) The slowest step in a metabolic pathway.Reaction intermediate（反应中间产物） Any chemical species in a reaction pathway that has a finite chemical lifetime.Reading frame（阅读框）A contiguous and nonoverlapping set of three-nucleotide codons in DNA or RNA.Recombinant DNA（重组DNA） DNA formed by the joining of genes into new combinations.Recombination(重组)Any enzymatic proce by which the linear arrangement of nucleic acid sequences in a chromosome is altered by cleavage and rejoining.Recombinational DNA repair（重组DNA修复）: recombinational procees that are directed at the repair of DNA strand breaks or cro-links, especially at inactivated replication forks.Redox pair（氧还对） An electron donor and its corresponding oxidized form; for example, NADH and NAD\"\".Redox reaction（氧还反应）: See oxidation-reduction reaction.Reducing agent (reductant)（还原剂） The electron donor in an oxidation-reduction reaction.Reducing end（还原端）The end of a polysaccharide having a terminal sugar with a free anomeric carbon; the terminal residue can act aa a reducing sugar.Reducing equivalent: A general or neutral term for an electron or an electron equivalent in the form of a hydrogen atom or a hydride ion.Reducing sugar（还原糖）A sugar in which the carbonyl Canomeric) carbon is not involved in a glycosidic bond and can therefore undergo oxidation.Reduction（还原）Tlie gain of electrons by a compound or ion.Regulatory enzyme（调节酶）An enzyme having a regulatory function through its capacity to undergo a change in catalytic activity by allosteric mechanisms or by covalent modification.

Regulatory gene（调节基因） A gene that gives rise to a product involved in the regulation of the expreion of another gene; for example, a gene coding for a repreer protein.Regulatory sequence（调节序列）A DNA sequence involved in regulating the expreion of a gene; for example, a promoter or operator. 5 3

Regulon（调节子） A group of genes or operons that are coordinately regulated even though some, or all, may be spatially distant within the chromosome or genome.Relaxed DNA（松弛DNA）Any DNA that exists in its most stable and unstrained structure, typically B form under most cellular conditions.Release factors（终止释放因子）See termination factors.Releasing factors: Hypothalamic hormones lhat stimulate release of other hormones by the pituitary gland, Renaturation（复性） Refolding of an unfolded (denatured) globular protein so as to restore native structure and protein function.Replication（复制）Synthesis of daughter nucleic acid molecules identical to the parental nucleic acids.Replication fork（复制叉）The Y-shaped structure generally found at the point where DNA is being synthesized.Replicative form（复制形式） Any of the full-length structural forms of a viral chromosome that serve as distinct replication intermediates.Replisome（复制体）The multiprotein complex that promotes DNA synthesis at the replication fork.Repreible enzyme（阻遏酶） In bacteria, an enzyme whose synthesis is inhibited when its reaction product is readily available to the cell.Repreion:（阻遏） A decrease in the expreion of a gene in response to a change in the activity of a regulatory protein.Repreer（阻遏蛋白）The protein that binds to the regulatory sequence or operator for a gene, blocking its transcription.Residue（残基） A single unit within a polymer; for example, an amino acid within a polypeptide chain.The term reflects the fact that sugars, nucleotides, and amino acids lose a few atoms (generallytne elements of water) when incorporated in their respective polymers.Respiration（呼吸）Any metabolic proce that leads to the uptake of oxygen and tlie release of COg.Respiration-linked phosphorylation（呼吸链磷酸化）ATP formation from ADP and Pp driven by electron flow through a series of membrane-bound carriers, with a proton gradient as the direct source of energy driving rotational catalysis by ATPsynthase, Respiratory chain（呼吸链） The electron transfer chain; a sequence of electron-carrying proteins that transfer electrons from substrates to molecular oxygen in aerobic cells.Restriction endonucleases（限制性内切酶） Site-specific endodeoxyribonucleases causing cleavage of both strands of DNA at points within or near the specific site recognized by the enzyme; important tools in genetic engineering.Restriction fragment（限制片段）A segment of double-stranded UNA produced by the 6 3

action of a restriction endonuclease on a larger DNA.Restriction fragment length polymorphisms (RFLPs) （限制片段长度多态性）: Variations, among individuals in a population, in the length of certain restriction fragments within which certain genomic sequences occur.These variations result from rare sequence changes that create or destroy restriction sites in the genome.Retrovirus（反转录病毒） An RNA virus containing a reverse transcriptase.Reverse transcriptase（反转录酶）: An RNA-directed DNA polymerase in retroviruses; capable of making DNA complementary to an RNA.Ribonuclease（核糖核酸酶）A nuclease that.catalyzes the hydrolysis of certain internucleotide linkages of RNA.Ribonucleic acid: （核糖核酸） See RNA.Ribonucleotide（核糖核苷酸）A nucleotide containing D-ribose as its pentose component.Ribosomal RNA （rRNA）（核糖体RNA） A cla of RNA molecules serving as components of ribosomes.Ribosome（核糖体）A supramolecular complex of rRNAs and proteins, approximately 18 to 22 imi in diameter; the site of protein synthesis.Ribozymes(核酶) Ribonucleic acid molecules with catalytic activities; RNA enzymes.Rieske iron-sulfur protein （Rieske铁硫蛋白） A type of iron-sulfur protein in which two of the ligands to the central iron ion are His side chains.These proteins act in many electron-transfer sequences, including oxidative phosphorylation and photophosphorylation.RNA (ribonucleic acid): A polyribunucleotide of a specific sequence linked by succeive 3\', 5\'-phosphodiester bonds.RNA polymerase（RNA聚合酶） An enzyme that catalyzes the formation of RNA from ribonucleoside S\'-triphosphates, using a strand of DNA or RNA as a template.RNA splicing（RNA拼接）Removal of introns and joining of exons in a primary transcript.rRNA: See ribosomal RNA.S S-adenosylmethionine (adoMet)（S-腺苷蛋氨酸或活化蛋氨酸）An enzymatic cofactor involved in methyl group transfers.Salvage pathway（补救途径）Synthesis of a biomolecule, such as a nucleotide, from intermediates in the degradative pathway for the biomolecule; a recycling pathway, as distinct from a de novo pathway.Saponification（皂化作用）Alkaline hydrolysis of triacylglycerols to yield fatty acids as soaps.Sarcomere（肌节）A functional and structural unit of the muscle contractile system. 7 3

Satellite DNA（卫星DNA） Highly repeated, nontranslated segments of DNA in eukaryotic chromosomes; most often aociated with the centromeric region.Its function is not clear.Saturated fatty acid(饱合脂肪酸) A fatty acid containing a fully saturated alkyl chain.Second law of thermodynamics（热力学第二定律）The law stating that in any chemical or physical proce, the entropy(熵) of the universe tends to increase.Second meenger（第二信使）An effector molecule synthesized within a cell in response to an external signal (first meenger) such as a hormone.Secondary metabolism（次生代谢）Pathways that lead to specialized products not found in every living cell.Secondary structure（二级结构） The residue-by-residue conformation of the backbone of a polymer.Sedimentation coefficient（沉降系数） A physical constant, specifying the rate of sedimentation of a particle in a centrifugal field under specified conditions.Selectins（选择蛋白）A large family of membrane proteins, lectins(凝集素) that bind oligosaccharides on other cells tightly and specifically, and serve to carry signals acro the plasma membrane.SELEX; A method for rapid experimental identification of nucleic acid sequences (usually RNA) that have particular catalytic or ligand-binding properties.Serpentine receptors（蜿蜒受体） A large family of membrane receptor proteins with seven trans-membrane helical segments.These receptors often aociate with G proteins to transduce an extracellular signal into a change in cellular metabolism.Shine-Dalgarno sequence（SD序列） A sequence in an mRNA required for binding prokaiyotic ribosomes.SH2 domain; A protein domain that binds tightly to a phosphotyrosine residue in certain proteins such as the receptor tyrosine kinases, initiating the formation of a multiprotein complex that acts in a signaling pathway.Shuttle vector（穿梭载体） A recombinant DNA vector that can be replicated in two or more different host species.See also vector.Sickle-cell anemia（镰刀型贫血病）A human disease characterized by defective hemoglobin molecules; caused by a homozygous allele coding for the β chain of hemoglobin.Sickle-cell trait（镰刀性状） A human condition recognized by the sickling of erythrocytes when exposed to low oxygen tension; occurs in individuals heterozygous for the allele responsible for sickle-cell anemia.Signal sequence（信号序列） An amino acid sequence, often at the amino terminus, that signals the cellular fate or destination of a newly synthesized protein.Signal transduction（信号传导） The proce by which an extracellular signal (chemical, mechanical, or electrical) is amplified and converted to a cellular response. 8 3

Silent mutation（沉默突变）A mutation in a gene that causes no detectable change in the biological characteristics of the gene product.Simple diffusion（简单扩散） The movement of solute molecules acro a membrane to a region of lower concentration, unaisted by a protein transporter.Simple protein（简单蛋白） A protein yielding only amino acids on hydrolysis, Site-directed mutagenesis（定点突变） A set of methods used to create specific alterations in the sequence of a gene.Site-specific recombination（定点重组） A type of genetic recombination that occurs only at specific sequences.Size-exclusion chromatography（分子排阻层析） A procedure for the separation of a mixture of molecules on the basis of size, based on the capacity of porous polymers to exclude solutes above a certain size.Also called gel filtration(凝胶过滤).Small nuclear RNA (snRNA)（小核RNA）Any of several small RNA molecules in the nucleus; most have a role in the splicing reactions that remove introns from mRNA, tRNA, and rRNA molecules.Somatic cells(体细胞) All body cells except the germ-line cells（生殖细胞）.SOS response（应急反应） In bacteria, a coordinated induction of a variety of genes as a response to high levels of DNA damage.Southern blot（Southern印迹法）A DNA hybridization procedure in which one or more specific DNA fragments are detected in a larger population by means of hybridization to a complementary, labeled nucleic acid probe.Specific acid-base catalysis（狭义酸碱催化） Acid or base catalysis involving the constituents of water (hydroxide or hydronium ions).Specific activity（比活力）The number of micromoles (µmol) of a substrate transformed by an enzyme preparation per minute per milligram of protein at 25 °C; a measure of enzyme purity.Specific heat（比热）The amount of energy (in joules焦耳 or calories) needed to raise the temperature of 1 g of a pure substance by 1 ºC.Specific rotation（比旋光度）The rotation, in degrees, of the plane of plane-polarized light （平面偏振光）(D-line of sodium，钠的D线) by an optically active compound at 5 °C, with a specified concentration and light path.Specificity（特异性，专一性） The ability of an enzyme or receptor o discriminate among competing substrates or ligands, Sphingolipid（神经鞘磷脂） An amphipathic lipid with a sphingosine（鞘氨醇） backbone to which are attached a long-chain fatty acid and a polar alcohol.Spliceosome（拼接体） A complex of RNAs and proteins involved in the splicing of mRNAs in eukaryotic cells.Splicing(拼接) See gene splicing; RNA splicing.Standard free-energy change (ΔG΄°)（标准自由能变化） The free-energy change for 9 3

a reaction occurring under a set of standard conditions: temperature, 298 K; preure, 1 atm or 101.3 kPa; and all solutes at 1 M concentration.ΔG΄° denotes the standard free-energy change at pH 7.0.Standard reduction potential (Έ’°): The electromotive force exhibited at an electrode by 1 M concentrations of a reducing agent and its oxidized form at 25 °C and pH 7.0; a measure of the relative tendency of the reducing agent to lose electrons.Steady state（稳态）A nonequilibrium state of a system through which matter is flowing and in which all components remain at, a constant concentration.Stem cells（干细胞）The common, self-regenerating cells in bone marrow(骨髓) that give rise to differentiated blood cells such as erythrocytes and lymphocytes.Stereoisomers（立体异构体） Compounds that have the same composition and the same order of atomic connections, but different molecular arrangements.Sterols（固醇类）A cla of lipids containing the steroid nucleus.sticky ends（粘性末端） Two DNA ends in the same DNA molecule, or in different molecules, with short overhanging single-stranded segments that are complementary to one another, facilitating ligation of the ends; also known as cohesive ends.Stop codons（终止密码）See termination codons.Stroma（叶绿体基质）The space and aqueous solution enclosed within the inner membrane of a chloroplast, not including the contents within the thylakoid membranes.Structural gene（结构基因）A gene coding for a protein or RNA molecule; as distinct, from a regulatory gene.Substitution mutation（碱基替换突变） A mutation caused by the replacement of one base by another.Substrate（底物） The specific compound acted upon by an enzyme.Substrate-level phosphorylation（底物水平磷酸化） Phoyphorylation of ADP or some other nucleoside 5\'-diphosphate coupled to the dehydrogenation of an organic substrate; independent of the electron-transfer chain（电子传递链）.Suicide inhibitor（自杀性抑制剂） A relatively inert molecule that is transformed by an enzyme, at its active site, into a reactive substance that irreversibly inactivates the enzyme.Supercoil（超螺旋） The twisting of a helical (coiled) molecule on itself; a coiled coil.Supercoiled DNA（超螺旋DNA）DNA that twists upon itself because it is under- or overwound (and thereby strained) relative to B-form DNA.Superhelical density（超螺旋密度）: In a helical molecule such as DNA, the number of supercoils (superhelical turns) relative to the number of coils (turns) in the relaxed molecule.Suppreor mutation（抑制基因突变）A mutation that totally or partially restores a function lost by a primary mutation; located at a site different, from the site of the primary mutation, 0

4 Svedberg (S): (沉降系数)A unit of measure of the rate at which a particle sediments in a centrifugal field.Symbionts（共生体） Two or more organisms that are mutually interdependent; usually living in physical aociation.Symport（共转运）Cotransport of solutes acro a membrane in the same direction.Synthases（合酶）Enzymes that.catalyze condensation reactions in which no nucleoside triphosphate is required as an energy source.Synthetases（合成酶）Enzymes that catalyze condensation reactions using ATP or another nucleoside triphosphate as an energy source.System（系统）An isolated collection of matter; all other matter in the universe apart from the system is called the surroundings（环境）.T Telomere（端粒）Specialized nucleic acid structure found at the ends of linear eukaryotic chromosomes.Template（模板） A macromolecular mold or pattern for the synthesis of an informational macromolecule.template strand（模板链）A strand of nucleic acid used by a polymerase as a template to synthesize a complementary strand.terminal transferase（末端转移酶） An enzyme that catalyzes the addition of nucleotide residues of a single kind to the 3\' end of DNA chains.termination codons（终止密码）UAA, UAG, and UGA; in protein synthesis, signal the termination of a polypeptide chain.Also known as stop codons.termination factors（终止因子） Protein factors of the cytosol required in releasing a completed polypeptide chain from a ribosome; also known as release factors.termination sequence（终止序列） A DNA sequence that appears at the end of a transcriptional unit and signals the end of transcription.Terpenes（萜类） Organic hydrocarbons or hydrocarbon derivatives constructed from recurring isoprene units.They produce some of the scents and tastes of plant products.tertiary structure（三级结构） The three-dimensional conformation of a polymer in its native folded state.Tetrahydrobiopterin（四氢生物喋呤）The reduced coenzyme form of biopterin（生物喋呤）.Tetrahydrofolate（四氢叶酸） The reduced, active coenzyme form of the vitamin folate(叶酸).

thiamine pyrophosphate（焦磷酸硫胺素）The active coenzyme form of vitamin B1; involved in aldehyde transfer reactions.Thioester（硫酯） An ester of a carboxylic acid with a thiol or mercaptan.3\' end: （3\'端）The end of a nucleic acid that lacks a nucleotide bound at the 3\' position of the terminal residue. 1 4

Thromboxanes（凝血恶烷类） A cla of molecules derived from arachidonate（花生四烯酸） and involved in platelet aggregation during blood clotting.Thylakoid（类囊体） Closed cisterna(囊), or disk, formed by the pigment-bearing internal membranes of chloroplasts.thymine dimer（胸腺嘧啶二聚体）See pyrimidine dimer.tiue culture（组织培养） Method by which cells derived from multicellular organisms are grown in liquid media.titration curve(滴定曲线) A plot of the pH versus the equivalents of base added during titration of an acid.Tocopherols（生育酚）Forms of vitamin E.topoisomerases（拓扑异构酶） Enzymes that introduce positive or negative supercoils in closed, circular duplex DNA.Topoisomers（拓扑异构体）Different forms of a covalently closed, circular DNA molecule that differ only in their linking number.Topology（拓扑学）The study of the properties of an object that do not change under continuous deformations such as twisting or bending.Toxins（毒素蛋白）Proteins produced by some organisms and toxic to certain other species.trace element（痕量元素） A chemical element required by an organism in only trace amounts.Transaminases（转氨酶）See aminotransferases（氨基转移酶）.Transamination（转氨作用）Enzymatic transfer of an amino group from an α-amino acid to an α-keto acid.Transcription（转录） The enzymatic proce whereby the genetic information contained in one strand of DNA is used to specify a complementary sequence of bases in an mRNA chain.transcriptional control（转录控制）The regulation of a protein\'s synthesis by regulation of the formation of its mRNA.Transduction[（能量）转换、（信息）传导] (1) Generally, the conversion of energy or information from one form to another.(2) The transfer of genetic information from one cell to another by means of a viral vector.transfer RNA (tRNA)（转移RNA）A cla of RNA molecules (M,.25,000 to 30,000), each of which combines covalently with a specific amino acid as the first step in protein synthesis.Transformation(转化)Introduction of an exogenous DNA into a cell, causing the cell to acquire a new phenotype.Transgenic（转基因的） Describing an organism that has genes from another organism incorporated within its genome as a result of recombinant DNA procedures.transition state（过渡态）An activated form of a molecule in which the molecule has 2

4 undergone a partial chemical reaction; the highest point on the reaction coordinate(反应进程图).Translation（翻译）The proce in which the genetic information present in an mRNA molecule specifies the sequence of amino acids during protein synthesis.translational control（翻译控制） The regulation of a protein\'s synthesis by regulation of the rate of its translation on the ribosome.translational repreer（翻译阻遏物）A repreer that binds to an mRNA, blocking translation.Translocase（转运酶、移位酶） (1) An enzyme that catalyzes membrane transport.(2) An enzyme that causes a movement, such as the movement of a ribosome along an mRNA.Transpiration（蒸腾作用）Paage of water from the roots of a plant to the atmosphere via the vascular system（脉管系统） and the stomata（气孔） of the leaves.Transporters（转运体） Proteins that span a membrane and transport specific nutrients, metabolites, ions, or proteins acro the membrane; sometimes called permeases.(透过酶) Transposition（转座） The movement of a gene or set of genes from one site in the genome to another.transposon (transposable element)（转座子）A segment of DNA that can move from one position in the genome to another.Triacylglycerol（三酰甘油）An ester of glycerol with three molecules of fatty acid; also called a triglyceride(三酰甘油酯) or neutral fat（中性酯）.tricarboxylic acid cycle（三羧酸循环） See citric acid cycle, triose（丙糖）A simple sugar with a backbone containing three carbon atoms.tRNA: See transfer RNA.tropic hormone (tropin)（促激素） A peptide hormone that stimulates a specific target gland to secrete its hormone; for example, thyrotropin(促甲状腺素) produced by the pituitary stimulates secretion of thyroxine（甲状腺素） by the thyroid（甲状腺）.turnover number（周转数） The number of times an enzyme molecule transforms a substrate molecule per unit time, under conditions giving maximal activity at substrate concentrations that are saturating.U Ubiquitin（泛蛋白） A small, highly conserved protein that targets an intracellular protein for degradation by proteasomes.Several ubiquitin molecules are covalently attached in tandem to a Lys residue in the target protein by a specific ubiquitinating enzyme.ultraviolet (UV) radiation（紫外辐射） Electromagnetic radiation in the region of 200 to 400 nm.uncompetitive inhibition（反竞争性抑制） The reversible inhibition pattern resulting 3

4 when an inhibitor molecule can bind to the enzyme-substrate complex but not to the free enzyme.uncoupling agent（解偶联剂） A substance that uncouples phosphorylation of ADP from electron transfer; for example, 2,4-dinitrophenol（2，4-二硝基苯酚）.Uniport（单向转运）A transport system that carries only one solute, as distinct from cotransport, unsaturated fatty acid（不饱合脂肪酸） A fatty acid containing one or more double bonds.urea cycle（尿素循环） A metabolic pathway in vertebrates, for the synthesis of urea from amino groups and carbon dioxide; occurs in the liver.Ureotelic（排尿素的）Excreting exce nitrogen in the form of urea.Uricotelic（排尿酸的） Excreting exce nitrogen in the form of urate (uric acid).V Vmax（最大反应速度）The maximum velocity of an enzymatic reaction when the binding site is saturated with substrate, Vector（载体） A DNA molecule known to replicate autonomously in a host cell, to which a segment of DNA may be spliced to allow its replication; for example, a plasmid or an artificial chromosome.Vectorial metabolism（方向性代谢） Metabolic transformations in which the location (not the chemical composition) of a substrate changes relative to a cellular membrane dividing two compartments.Transporters catalyze vectorial reactions, as do the proton pumps of oxidative and photophosphorylation.viral vector（病毒载体）A viral DNA altered so that it can act as a vector for recombinant DNA.Virion（病毒粒）A virus particle.Virus（病毒）A self-replicating, infectious, nucleic acid-protein complex that requires an intact host cell for its replication; its genome is either DNA or RNA.Vitamin（维生素） An organic substance required in small quantities in the diet of some species; generally functions as a component of a coenzyme.W wild type（野生型） The normal (unmutated) phenotype.Wobble（摆动、变偶） The relatively loose base pairing between the base at the 3\' end of a codon and the complementary base at the 5\' end of the anticodon.X x-ray crystallography（X-射线晶体学）The analysis of x-ray diffraction patterns of a crystalline compound, used to determine the molecule\'s three-dimensional structure.Z zinc finger (锌指)A specialized protein motif(基序)involved in DNA recognition by 4 4

some DNA-binding proteins, characterized by a single atom of zinc coordinated(配位) to four Lys residues or to two His and two Lys residues.Zwitterion（兼性离子）A dipolar ion, with spatially separated positive and negative charges.Zymogen（酶原） An inactive precursor of an enzyme; for example, pepsinogen(胃蛋白酶原), the precursor of pepsin（胃蛋白酶）.

5 4

生物化学双语教学单词

生物化学教学大纲(双语)

生物化学双语教学的探讨

生物化学双语教学的尝试与问题分析

浅谈高等院校双语教学在生物化学课程中的应用 OK最后

词汇教学中问题

生物化学教学总结

生物化学教学总结

《医学生物化学》中的PBL教学探讨

词汇教学中的PWP

《双语教学中的生物化学词汇.doc》

将本文的Word文档下载到电脑，方便编辑。

推荐度：

点击下载文档