生物化学上册-第二章双语PPT课件

.,1,Chapter2.Carbohydrates,IntroductionMonosaccharides(单糖)Oligosaccharides(寡糖)Polysaccharides(多糖)Glycoconjugates(复合糖)Analysisofcarbohydrates,.,2,I.Introduction,ExistenceFunctions(功能)Definition(定义)Classification(分类)Characteristicchemicalfeatures(化学通性),.,3,1.Existence,ThemostabundantclassoforganicmoleculesfoundinnatureWidelydistributedinplantsandanimalsOriginatedfromphotosynthesisBasiccomposition:C,H,O(N,P,S)Empiricalformula:(CH2O)nConstitutingaversatileclassofmoleculesMono-/oligo-/polysaccharides(单糖/寡糖/多糖)Derivatives(衍生物)Glycoconjugates(复合糖),I.Introduction,P.1,.,4,2.Function,Storageofenergy(能量贮存)Structuralelements(结构成分)Precursors(前体)/intermediates(中间物)ofotherbiomoleculesCellrecognition(细胞识别),I.Introduction,P.1,.,5,3.Definition,葡萄糖,果糖,甘油醛,二羟基丙酮,Carbohydratesarepolyhydroxyaldehydesorketones(多羟基醛/多羟基酮)orsubstancesthatyieldsuchcompoundsonhydrolysis.,.,6,4.Classification,Threemajorclassesofcarbohydrates,I.Introduction,.,7,5.Characteristicchemicalfeatures(化学通性),Existenceofoneormoreasymmetriccenters(不对称中心)Abilitytoexisteitherinlinearorringstructures(线状或环状结构)Capacitytoformpolymericstructuresviaglycosidicbonds(糖苷键连接)Potentialtoformmultiplehydrogenbondswithwaterorothermolecules(形成氢键的能力),I.Introduction,P.2,.,8,Twofamilies:aldosestheyareepimersandanomerswithdifferentproperties.(-D-glucose和-D-glucose不是互为对映异构体，是差向异构体和异头物，具有不同的物理/化学性质。),.,27,Mutarotation(变旋),36%20D=+112.2o146oCm.p.,64%20D=+18.7o148-155oCm.p.,(0.024%),Atequilibrium,20D=+52.6o,.,28,Cyclicstructure(4):Pyranoses&furanoses,Pyranoses（吡喃糖）,Furanoses（呋喃糖）,II.Monosaccharides,P.10,.,29,-D-吡喃葡糖,-D-吡喃葡糖,-D-呋喃葡糖,-D-呋喃葡糖,-D-吡喃果糖,-D-吡喃果糖,-D-呋喃果糖,-D-呋喃果糖,D-glucose,D-fructose,.,30,Cyclicstructure(5):Conformation,ForD-glucose,-formismorestablethan-form.Forotheraldohexoses,-formismorestablethan-form.,Twopossiblechairconformationsof-D-glucose,II.Monosaccharides,P.13,.,31,4.Properties,Physicalproperties(物理性质):Opticalactivity&mutarotation(旋光性和变旋):SeeTable1-1,P.14Sweetness(甜度):SeeTable1-2,P.15Solubility(溶解度):P.15AllsolubleinH2Oexceptglyceraldehyde(除甘油醛外均为水溶性)insolubleinnonpolarorganicsolvents(不溶于非极性有机溶剂)Chemicalproperties(化学性质),II.Monosaccharides,.,32,Chemicalproperties,Isomerization(异构化)Oxidation(氧化)Reduction(还原)Formationofosazone(糖脎)Formationofsugarester(糖酯)andsugarether(糖醚)Formationofglycoside(糖苷)Dehydration(脱水)Elongationandshorteningofmonosaccharidechain(单糖链的延长和缩短),II.Monosaccharides,P.15,.,33,21%,2.5%,ChemicalProperties(1):keto-enoltautomerism(酮-烯醇互变异构),II.Monosaccharides,63.5%,P.15-16,.,34,ChemicalProperties(2):Oxidation,CH=O,CH2OH,OH,OH,OH,HO,COOH,CH2OH,OH,OH,OH,HO,CH=O,COOH,OH,OH,OH,HO,COOH,COOH,OH,OH,OH,HO,Cu2+OH-,Dehydrogenase(脱氢酶),HNO3,Aldonicacid醛糖酸,Uronicacid糖醛酸,Aldaricacid醛糖二酸,Sugaracids(糖酸),Br2/H2O,.,35,Oxidizingagents(氧化剂):H2O2,Ag+,Fe3+,Cu2+Fehlingreagents:tartrate(酒石酸钾钠)，NaOH,CuSO4Benedictreagents:citricacid(柠檬酸),Na2CO3,CuSO4Reducingsugar(还原糖):Capableofreducingoxidizingagents(可以还原以上的氧化剂)Allaldosesandmanyketosesarereducingsugars(所有醛糖和多数酮糖)Fructoseisareducingsugar(果糖是还原糖),Aqualitativetestforreducingsugars(还原糖),P.16,(Redprecipitate),还原糖的定性检测,.,36,ChemicalProperties(2):Oxidation(continued),CH=O,CH2OH,OH,OH,OH,HO,H,H,H,H,HCOOH,4HCOOH,HCHO,+,+,IO4-,Thisreactionisspecificforaldoses.(此反应只适用于醛糖),Thisreactionisusefulinprovidingstructuralinformation(此反应可帮助分析糖的结构),II.Monosaccharides,.,37,1,2-linkage,1,4-linkage,1,6-linkage,OxidationbyIO4-,P.72,.,38,ChemicalProperties(3):Reduction,CH=O,CH2OH,OH,OH,OH,HO,CH2OH,CH2OH,OH,OH,OH,HO,CH2OH,CH2OH,OH,HO,CH=O,CH2OH,OH,HO,HO,HO,NaBH4,NaBH4,180o,Rotation,D-葡萄糖,D-葡萄醇,L-古洛糖,L-古洛醇,C=O,CH2OH,HO,OH,OH,CH2OH,C=O,CH2OH,HO,OH,CH2OH,HO,HO,HO,D-果糖,L-山梨糖,NaBH4,NaBH4,Sugaralcohols(糖醇),.,39,Sugaralcohols(糖醇),CH2OH,CH2OH,OH,OH,OH,HO,D-Glucitol(D-葡萄醇),Sorbitol(山梨醇）,CH2OH,CH2OH,OH,OH,HO,D-Mannitol(D-甘露醇),HO,CH2OH,CH2OH,OH,OH,HO,D-Xylitol(D-木糖醇),CH2OH,CH2OH,OH,Glycerol(甘油醇),H,H,H,H,H,H,H,H,H,H,H,H,II.Monosaccharides,.,40,ChemicalProperties(4):Formationofosazone（糖脎）,苯肼,苯脎(黄色晶体),Thisreactionisusefulincharacterizingreducingsugars(此反应用于鉴定还原糖).,YellowcrystalswithDifferentcrystalshapesDifferentmeltingpoints,II.Monosaccharides,.,41,ChemicalProperties(5):SugarEsters&SugarEthers(糖酯和糖醚),Acetylation(乙酰化),Methylation(甲基化),Phosphorylation(磷酸化),P.19,.,42,OH,OH,HO,CH2OH,H,H,H,OH,H,O,OH,OH,HO,CH2OH,H,H,H,O-CH3,H,O,Hemiacetal(半缩醛),Acetal(缩醛),Glycone(糖基),Aglycone(配基),Glycosidicbond(糖苷键),ChemicalProperties(6):Glycoside(糖苷),Glycoside(糖苷),Monosaccharide(单糖),II.Monosaccharides,Glycosidicbondisunstableunderacidicconditions.(糖苷键在酸性条件下不稳定),P.19,H+,Reducingsugar,Non-reducingsugar,.,43,ChemicalProperties(7):Dehydration,5-Hydroxymethylfurfural5-羟甲糠醛,Differentfurfuralsreactwithpolyphenolstogeneratedifferentspecificcolors,thereforethisreactionisusefulincharacterizingthemonosaccharides.(用于单糖的定性检测),II.Monosaccharides,P.20,.,44,糠醛,-萘酚,蒽酚,红紫色缩合物(Molishtest),糠醛,蓝绿色复合物(蒽酚反应),5-羟甲糠醛,鉴定酮糖,鉴定戊糖,鉴定糖类,测定总糖量,糠醛,.,45,5.Importantmonosaccharidesandtheirderivatives,MonosaccharidesSugarphosphateesters(单糖磷酸酯)Sugaralcohols(糖醇)Sugaracids(糖酸)Sugaresters(糖酯)Sugarethers(糖醚)Deoxysugars(脱氧糖)Aminosugars(氨基糖)Glycosides(糖苷),II.Monosaccharides,P.22,Adenosinetriphosphate(ATP),.,46,III.Oligosaccharides(寡糖),Glycosidicbonds(糖苷键)Nomenclature(命名)Someoligosaccharides,Oligosaccharidearesaccharidesconsistingof2-20monosaccharideunitsjoinedcovalentlybyanO-glycosidicbond.,.,47,1.Glycosidicbonds(糖苷键),Formation:由一个单糖的异头碳上的羟基和另一个单糖的任一个C上的羟基缩合而成bycondensationof-OHgroupattheanomericC(异头碳上的羟基)fromonesugar-OHgroupfromanothersugarReducingend(还原端):-withafreeanomericCNonreducingend(非还原端)：-withoutafreeanomericCAnoligosaccharidewithareducingendisareducingsugar(有还原端的寡糖是还原糖).Stabilityofglycosidicbonds(糖苷键的稳定性):Hydrolyzedbyacid(被酸水解)Stableinalkalinesolution(对碱稳定),麦芽糖,III.Oligosaccharides,P.34,Reducingend(还原端),Nonreducingend(非还原端),.,48,Maltose（麦芽糖）Glucose-1,4-glucose,Cellobiose（纤维二糖）glucose-1,4-glucose,Isomaltose（异麦芽糖)Glucose-1,6-glucose,O-D-glucopyranosyl-(14)-D-glucopyranoseO-D-吡喃葡糖基-(14)-D-吡喃葡糖,Glc(14)Glc,(14),(16),(14),.,49,2.Nomenclature(命名),-乳糖半乳糖-葡萄糖Gal(14)Glc,蔗糖葡萄糖-果糖Glc(12)FruFru(21)Glc,海藻糖葡萄糖-葡萄糖Glc(11)Glc,Nonreducingsugars,Reducingsugars,O-D-吡喃半乳糖基-(14)-D-吡喃葡糖,P.35,单糖的缩写见P.31，表1-4,.,50,3.Someoligosaccharideexamples,Sucrose(蔗糖)：Glc(12)FruLactose(乳糖)：Gal(14)GlcMaltose(麦芽糖)：Glc(14)GlcGentianose(龙胆糖):Glc(16)Glc(12)FruCyclodextrin(环糊精):P.40Cyclicstructureformedby6-8glucoseresiduesthrough-1,4-glycosidiclinkage,III.Oligosaccharides,P.36-40,.,51,Cyclodextrins(环糊精),(14),-OHatC-6,-OHatC-2,C-3,HydrophobicInside(内部疏水),HydrophilicOutside(外部亲水),readilydissolveinwateradsorbhydrophobicmoleculestotoformwater-solubleinclusioncomplexsothattheirchemical/physicalpropertiescanbechanged,e.g.,increasedsolubilityhigherstabilityagainstlight,heatandoxygenwidelyusedasstabilizer,anti-oxidant,emulsifier,solubilityenhancer,etc.,.,52,IV.Polysaccharides(多糖),ExistenceClassificationHomopolysaccharides(同多糖)Hetereopolysaccharides(杂多糖),.,53,1.Existence,Mostcarbohydratesfoundinnatureoccuraspolysaccharides.Consistingofmorethan20monosaccharides.Molecularweight(分子量)of300004x108ThemostcommonconstituentisD-glucosePolysaccharidesdifferfromeachotherin:Natureofthecomponentmonosaccharides(单糖)Lengthofthechains(链长)Typesofthebondslinkingtheunits(糖苷键)Degreeofchainbranching(支链程度)Nonreducingsugars(非还原糖)Nomutarotation(没有变旋现象)Nosweetness(无甜味),IV.Polysaccharides,P.40,.,54,2.Classification,Biologicalsources(生物来源)Plant,animal,microorganismBiologicalfunctions(生物功能)Storagepolysaccharides(贮存多糖)e.g.starch(淀粉)Structuralpolysaccharides(结构多糖)e.g.cellulose(纤维素)InformationcarriersCompositions(组成)Homopolysaccharides(同多糖)Heteropolysaccharides(杂多糖),IV.Polysaccharides,.,55,3.Homopolysaccharides(同多糖),.,56,Amyloselong,unbranchedchains(14)linkageAmylopectinhighlybranched(14)tojoinsuccessiveglucoseresidues(16)linkagesatbranchpoints,Starch:Amylose&amylopectin（直链淀粉&支链淀粉）,P.41,14,Ashortsegmentofamylose(直链淀粉),(16),(14),Asegmentofamylopectin(支链淀粉),.,57,Amylose（直链淀粉）,14,.,58,Aclusterofamyloseandamylopectin,.,59,Amylose&amylopectin(直链和支链淀粉),Bothhavecoiledhelicalstructuresdueto14linkages(都是螺旋结构)BotharecharacterizedbyreactionwithI2(都与I2发生特征反应)Amylose(直链淀粉)darkblue(深蓝色)Amylopectin(支链淀粉)purple(紫色)Bothhaveareducingend(都有一个还原端)EasilyhydratedbecauseofOHgroupsreadytoformH-bondswithwater(都易于水合，因为易与水形成氢键)Ingestedbyhydrolysiswithamylases(淀粉酶水解而被吸收)Amylasesarecapableofcleavingstarchandglycogen:,P.42Fig.1-24,.,60,Cellulose（纤维素）,IV.Polysaccharides,P.45,14,.,61,Cellulose,(14)linkageFlattenedsheetstructure(片层结构)verystableInterchainandintrachainH-bonds(链间/链内氢键)Extremelyresistanttohydrolysis(不易水解)Insolubleinwater(不溶于水)Ingestedonlybyruminantanimals(只能被反刍动物吸收):hydrolysisbycellulases(纤维素酶),IV.Polysaccharides,P.46Fig.1-27,.,62,Agar(琼脂):P.49Hemicellulose(半纤维素):P.48Peptidoglycan(肽聚糖):P.51Glycosaminoglycan(糖胺聚糖):P.66,4.Hetereopolysaccharides（杂多糖）,IV.Polysaccharides,.,63,Agarose(琼脂糖),Agar(琼脂),Agarose(琼脂糖),Agaropectin(琼脂胶),IV.Polysaccharides,Sepharose(琼脂糖凝胶),P.49,Three-dimensionalstructure:adoublehelixwithathree-foldscrewaxis.Cantakeup99.5%H2OYieldSepharoseasasupportusedingelfiltrationchromatography.,.,64,Peptidoglycan(肽聚糖)majorcomponentinthebacterialcellwalls,IV.Polysaccharides,金黄色葡萄球菌(agram-positivebacterium),P.51-53,P.53图1-31,Muropeptide(胞壁肽)14,Lysozymehydrolyzesthe14glycosidicbond,Penicillinpreventsthesynthesisofcross-links,.,65,Glycosaminoglycan(糖胺聚糖),Heparin(肝素),己糖醛酸己糖胺n,P.66-69,.,66,V.Glycoconjugates（复合糖）,Proteoglycans(蛋白聚糖):P.69Oneormoreglycosaminoglycan(糖胺聚糖)chainsarejoinedcovalentlytoamembraneprotein(膜蛋白)orasecretedprotein(分泌蛋白)Suga