生物化学(1)

1生物化学（1）杨缜Office:实验楼S-329Tel.:[phone]e-mail:[e-mail]2AboutthiscourseWhatisBiochemistry?Whyisthiscoursesoimportant?Howisthiscourseorganized?3英文网站深大主页教学服务网上课程多媒体教学资源本校教师开发的教学资源生物化学英文学习网站参考教材LehningerPrinciplesofBiochemistry,4thedition(2005)DavidL.NelsonandMichaelM.CoxW.H.FeeemanandCompany主要教材《生物化学》第三版（上册）4ContentsChapter1.GeneralintroductionChapter2.CarbohydratesChapter3.LipidsChapter4.Aminoacids,peptidesandproteinsChapter5.ProteinstructureChapter6.EnzymesChapter7.NucleotidesandnucleicacidsChapter8.Vitaminsandcoenzymes5Chapter1.GeneralIntroductionI.Livingorganismsvs.inanimateobjectsII.BiomoleculesIII.WaterandbufferIV.Experimentalapproachandmethodsusedinbiochemistry6I.Livingorganismsvs.inanimateobjectsChemicalcomplexityandorganizationCapacityforextracting,transforming,andusingenergyfromenvironmentsCapacityforself-replicationandself-assembly7II.Biomolecules1.Majortypesofbiomolecules2.Biomolecularhierarchy3.Chemicalprinciplesgoverningpropertiesofbiomolecules8Component%cellweightNo.ofdiff.mol.speciesWater701Proteins(蛋白质)153000NucleicacidsDNA11RNA63000Carbohydrates(糖)35Lipids(脂)220Subunits&intermediates2500Inorganicions(无机盐)120MolecularComponentsofanE.ColiCell9NormalChemicalCompositionforaManWeighing65kgWater61.6%,40kgProtein17.0%11kgFat13.8%,9kgMinerals6.1%,4kgCarbohydrate1.5%,1kg101.MajortypesofbiomoleculesBiomoleculePolymerofBiologicalactivitiesProteins(蛋白质)Aminoacids(MW5000-106)Catalysts-enzymesStructuralelementsSignalreceptorsTransportersNucleicacids(核酸)Nucleotides(MW~109)Storing&transmittinggeneticinfoStructuralrolesCarbohydrates(糖)Sugars(MW~106)Energy-yieldingfuelstoresExtracellularstructuralelementsLipids(脂)(MW750-1500)StructualcomponentsEnergy-richfuelstoresPigmentsIntracellularsignalsBiomoleculesaremacromoleculesthatarepresentinlivingorganismswithbiologicalactivities.11Elementarycompositionofthehumanbody(dryweightbasis)C:60%O:20%H:10%N:8.5%CaPKSNaClMgFeMnI%%C60S0.8O20Na0.4H10Cl0.4N8.5Mg0.1Ca4Fe0.01P2.5Mn0.001K1I0.00005Ca122.BiomolecularhierarchyInorganicprecursors(无机物前体)18-64daltonsCO2,H2O,NH3,N2,NO3-Metabolites(代谢物)50-250daltonse.g.pyruvate,citrateBuildingblocks100-350daltonse.g.aminoacids,nucleotidesMacromolecules103-109daltonse.g.proteins,lipidsSupramolecularcomplexes106-109daltonse.g.ribosomes,chromosomesOrganellese.g.nucleus,mitochondria,chloroplastsThecellUnitoflife13Structuralhierarchyinthemolecularorganizationofcells14AclassicexperimentontheabioticoriginoforganicbiomoleculesbyMillerandUrey(1953)Products:Gasphase:CO,CO2Liquidphase:aminoacids,aldehyde,HCN,etc.Prebioticevolutionperiod:BiomoleculeswerefirstarosebychemicalevolutionLighteningdischargeselectricalenergyVolcanoesheatenergy153.Chemicalprinciplesgoverningpropertiesofbiomolecules1).Elementarycompositions(元素组成)2).Molecularstructures(分子结构)3).Stereospecificinteractions(立体专一的相互作用)4).4typesofnoncovalentinteractions(非共价作用)5).5typesofchemicalreactionsincells(细胞内的化学反应)Chemistryisthelogicofbiologicalphenomena.161).BiomoleculesarecompoundsofCCovalentlinkagewithH,O,N,C:4mostabundantelementsCskeletons(骨架):linear,branched,cyclicFunctionalgroups(功能团):-OHHydroxygroupR-OHAlcohol-NH2AminogroupR-NH2AmineC=OCarbonylgroupR1-CO-R2Aldehyde,ketone-COOHCarboxylgroupR-COOHCarboxylacidNNNNNH2OOHOHHHHHOPOO-OPOO-OP-OO-O17Composition(组成)–e.g.,C4H4O4Constitution(构造)–e.g.,HOOC-CH=CH-COOHConfiguration(构型)–changedbybondbreakageConformation(构象)–changedbybondrotation2).Molecularstructures(分子结构)P.318马来酸富马酸视网膜醛19StereoisomersarecompoundsthathaveSamecomposition(相同组成)Differentconfigurations(不同构型)StereoisomersarecausedbythepresenceofDoublebonds:cis-transisomers(顺反异构)Chiralcenters:nchiralcarbons2nmaxstereoisomerse.g.C*ABXYe.g.C*HX(CH3)-C*HY(CH3)TwotypesofstereoisomersEnantiomers(对映异构体)–Mirrorimages–SamephysicalandchemicalpropertiesDiastereomers(非对映异构体)–Non-mirrorimages–DifferentphysicalandchemicalpropertiesStereoisomers(异构体)20Enantiomersanddiastereomers(对映异构体和非对映异构体)21PropertiesofStereoisomersEnantiomers:identicalphysicalandchemicalpropertiesinachiralenvironmentsCCHHOCOOHHCOOHOHCCHHOCOOHHOCOOHHm.p.146o174opK13.232.98Diastereomers:differentcompounds,differentphysicalandchemicalpropertiesCCHOHCOOHHCOOHHOCCHHOCOOHHCOOHOHm.p.174o174opK12.982.98对映异构体：性质相同非对映异构体：性质不同22Molecularasymmetry:Chiralandachiralmolecules(手性和非手性分子)C*ABXYChiral--notsuperimposableonthemirrorimageAchiral--superimposableonthemirrorimageHHHHOHHHOHHHHHMoleculeswithmorethanonechiralcentersmaynotnecessarilybechiral.(有一个以上手性C的分子不一定就是手性分子)**23香芹酮24Enzyme–substrate(酶-底物)Antigen–antibody(抗原-抗体)Hormone–receptor(激素-受体)3).Stereospecificinteractions(立体专一的相互作用)25H-bonds(氢键)Ionicinteractions(离子键)Hydrophobicinteractions(疏水相互作用)vanderWaalsinteractions(范德华力)4).Noncovalentinteractions(四种非共价相互作用)Importance:Determiningtheintra/intermolecularinteractions(决定分子内/分子间的相互作用)Maintainingthe3-dimensionalstructure(维持三维空间结构)Determiningthebiologicalfunction(决定生物功能)26Stabilizationenergy(kJ/mol)8-21424-8427Oxidation-reduction(氧化还原反应)Cleavage&formationofC-CbondsInternalrearrangements(内部重排)Grouptransfers(基团转移)Con