中南大学 生物化学 考研课件 ch14 酶动力学 enzyme kinetics06.ppt

BiochemistryChapter14EnzymekineticsIntroductiontoenzymes酶（学）导论PowerfulCatalyticpower强的催化力
Increasereactionrateupto1016fold
MakereactiontakenplaceunderrelativelymildconditionsoftemperatureandpH
Highspecificity高的特异性
Tothesubstratesthattheyactonandtheproductstheyform
Enzymeactivitycanberegulated酶活性可以被调控
Basicallyareproteins,exceptfewribozymes除了少量的核酶外,基本上是蛋白质Sometermsofenzymes酶的几种术语Enzymesareclassifiedintosixclassesbasedonthetypeofreactioncatalyzed基于催化反应的类型,酶可分为六种类型EnzymesareclassifiedintosixclassesbasedonthetypeofreactioncatalyzedTraditionalNomenclatureofenzymesSystematicnomenclature: Eachenzymeisuniquelyidentifiedbya four-digitclassificationnumberExpressionofenzymeactivity酶活性的表示Expressionofenzymeactivity酶活性的表示Someexpressionsofthecomponentsofanenzyme酶的成分的几种表示方式Cofactors辅助因子Theimportantcoenzymesandprostheticgroups重要的辅酶和辅基Watersolublevitamins(VitaminB)
Thiamine(B1)硫胺素
InCoenzymes：thiaminepyrophosphate存在于硫胺焦磷酸辅酶中
Riboflavin(核黄素B2)
Asprostheticgroupflavinprotein:FADandFMN
Nicotinicacid(niacin烟碱酸)
InCoenzymes:NADandNADP
Pantothenicacid(泛酸）
InCoenzymeA
Biotin(生物素）
Inprostheticgroup:Biocytin生物胞素
Lipidsolublevitamins(VitaminA,D,E,K)
VitaminA
Retinal视网膜素：vision,growthandreproductionSomecommoncoenzymes,theirvitaminprecursorsanddeficiencydiseasesCoenzymeANAD+,NADP+NAD(P)++H++2e-FAD,FMNFAD,FMNChemicalstructureofbiotinChapter14EnzymekineticsCofactors辅助因子(SEEthelastsection)
pH
Temperature
Substrateconcentration底物浓度
ProductconcentrationEffectofpH
EffectoftemperatureEnzymeassays酶的检测LDH:lactatedehydrogenase乳酸脱氢酶葡萄糖氧化酶Chapter14EnzymekineticsEnzymekineticsandinhibition(酶动力学和抑制作用)EnzymescatalyzechemicalreactionthroughloweringitsactivationenergyActivationEnergy~RateConstantofReactionG‡~kQuestions(selfstudy)
Whatdoesdynamicequilibriummean?
Enzymescanacceleratetheattainmentoftheequilibriumposition,canitchangethisposition?
What’sroleofactivesiteofanenzyme?
Bywhichforcesthesubstratebindstotheactivesiteofanenzyme?Michaelis-MentenmodelDoublereciprocalorlineweaver-BurkplotV0Enzymeinhibition酶的抑制