生物化学chap7respirationandenergy.ppt

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,Electron-transport chain,Oxidative,phosphorylation,Chap 7 Respiration and energy,(2),Energy yield,(3)Physiological importance,(1),biochemical reactions,CO,2,NADH,FADH,NADPH,电子传递链,H,2,O,ATP,Electron transport and oxidative phosphorylation,re-oxidize NADH and,FADH,2,and trap the energy released as,ATP,.,Introduction,In,eukaryotes(,真核细胞,),electron transport and oxidative phosphorylation occur in the inner membrane of,mitochondria(,线粒体,),whereas in,prokaryotes(,原核生物,),the process occurs in the,plasma,memebrane.,attention,Concept,Electron transport chain(respiratory chain)consists of a series of,electron carriers,by which electrons are transferred from NADH(FADH,2,),to oxygen.,Electron-transport chain,琥珀酸脱氢酶,(黄素脱氢酶类),NAD,脱氢酶,辅酶,Q,细胞色素类,2,H,Unlike,substrate level phosphorylation,it does not involve phosphorylated,chemical inermediates,.Rather,the energy that liberated by,electron transport,is used to drive the synthesis of ATP from ADP and Pi(,catalyzed by ATP synthase,).,.,attention,substrate level phosphorylation,底物水平磷酸化,有机物氧化过程中由于底物分子内部能量重新分布形成高能磷酸键，转给,ADP,形成,ATP。,the sequence of transport,all of the electron carriers in the transport chain interact according to their,redox,potentials,(,还原力,).Every time that an electron transfer occurs,the accepting carrier has a higher affinity for electrons than the donating carrier.,Thus there is a net flow of electron from NADH to oxygen.,The position of ATP synthesis,氧化还原电位（,E,0,）,：pH7.0，30,测得。表征物质得失电子趋势。电子总是从低氧化还原电位流向高电位。,E,0,越低，供电子倾向越大。,G,：0，,表示反应是自发过程。,GnF,Un96487（E,02,E,01,）30.5kJ,Amounts of ATP,P/O,:the number of Pi used When one oxygen atom is oxidized to generate H,2,O.,NADH+H,+,+,3ADP,+,3Pi,+1/2O,2,NAD,+,+4H,2,O+,3ATP,FADH,2,+,2ADP,+,2Pi,+1/2O,2,NAD,+,+3H,2,O+,2ATP,The mechanism of ATP synthesis,Chemiosmotic,hypothesis,(,化学渗透假说,),This proposes that,energy liberated by electron transport is used to create a,proton gradient across the,mitochondrial,inner membrane,and that it is this that is used to drive ATP synthesis.,