四、呼吸链的电子传递在线粒体内膜两侧形成质 子梯度( A proton gradient across the inner membrane of mitochondria is generated using the electron motive force e An estimate of 10 protons are pumped for oxidizing one NADH and 6 for one FADh2 accompanying the electron flow through complexes I, III and iv e Conformational changes induced by electron transferring is believed to be coupled to proton pumping(however, the actual mechanisms is yet revealed e In actively respiring mitochondria, the measured Aph is about 0.75 and difference in electrical potential (Ap)is about 0.15-0.2V e The energy stored in such an H* gradient can be used to synthesize atP or to do other work
An estimate of 10 protons are pumped for oxidizing one NADH and 6 for one FADH2 accompanying the electron flow through complexes I, III and IV. Conformational changes induced by electron transferring is believed to be coupled to proton pumping (however, the actual mechanisms is yet revealed!). In actively respiring mitochondria, the measured pH is about 0.75 and difference in electrical potential () is about 0.15-0.2 V. The energy stored in such an H+ gradient can be used to synthesize ATP or to do other work. 四 、呼吸链的电子传递在线粒体内膜两侧形成质 子梯度（A proton gradient across the inner membrane of mitochondria is generated using the electron motive force ）
五、呼吸链顺序的实验证据( The order of the many electron carriers on the respiratory chain have been elucidated via various studies) o Measurement of the standard reduction potential(AE( Electrons tend to transfer from low E0 carriers to high E0 carriers (but may deviate from this in real cells) Oxidation kinetics studies: Full reduction followed by sudden O introduction, earlier oxidation, closer to the end of the respiratory chain; using rapid and sensitive spectrophotometric techniques to follow the oxidation of the cytochromes, which have different wavelength of maximal absorption Effects of various specific inhibitors: those before the blocked step should be reduced and those after be oxidized Isolation and characterization of each of the multiprotein complexes: specific electron donors and acceptors can be determined for portions of the chain
Measurement of the standard reduction potential (E`0)): Electrons tend to transfer from low E`0 carriers to high E`0 carriers (but may deviate from this in real cells). Oxidation kinetics studies: Full reduction followed by sudden O2 introduction; earlier oxidation, closer to the end of the respiratory chain; using rapid and sensitive spectrophotometric techniques to follow the oxidation of the cytochromes, which have different wavelength of maximal absorption. Effects of various specific inhibitors: those before the blocked step should be reduced and those after be oxidized. Isolation and characterization of each of the multiprotein complexes: specific electron donors and acceptors can be determined for portions of the chain. 五、呼吸链顺序的实验证据（The order of the many electron carriers on the respiratory chain have been elucidated via various studies）
六|。 atP would not be synthesized when 线 only adp and p; are added in isolated 与粒 mitochondria suspensions 体 eO consumption, an indication of 中 electron flow. was detected when a reductant(e.g, succinate) is added 呼 accompanied by an increase of ATP 成的偶联 吸| synthe esIs 链 e Both o consumption and atp it synthesis were suppressed when 子传递 inhibitors of respiratory chain(e.g cyanide, co, or antimycin A)was added
六 线 粒 体 中 呼 吸 链 电 子 传 递 与ATP 合 成 的 偶 联 ATP would not be synthesized when only ADP and Pi are added in isolated mitochondria suspensions. O2 consumption, an indication of electron flow, was detected when a reductant (e.g., succinate) is added, accompanied by an increase of ATP synthesis. Both O2 consumption and ATP synthesis were suppressed when inhibitors of respiratory chain (e.g., cyanide, CO, or antimycin A) was added
ATPsynthesis depends on the occurrence of electron flow in mitochondria O, consumption was neither observed ifADP was not added to the suspension, although a reductant is provided The o, consumption was also not observed in the presence of inhibitors of ATP synthase(e.g oligomycin or venturicidin) Electron flow also depends on ATP synthesis
ATP synthesis depends on the occurrence of electron flow in mitochondria. O2 consumption was neither observed if ADP was not added to the suspension, although a reductant is provided. The O2 consumption was also not observed in the presence of inhibitors of ATP synthase (e.g., oligomycin or venturicidin). Electron flow also depends on ATP synthesis!
七、电子传递与ATP合成的偶联机制( The chemiosmotic model was proposed to explain the coupling of electron flow and ATP synthesis) x First proposed in 1961 by Peter Michell(a British) x Energy released from electron transferring is hypothesized to be first used to pump protons from the mitochondrial matrix to the intermembrane space (or from stroma to thylakoid lumen in chloroplasts), thus generating a proton gradient across the inner membrane; such a proton-motive force then drives ATP synthesis by moving protons back into the matrix via the atP synthase-- The chemiosmotic model. x The model was initially opposed by virtually all researchers working in oxidative phosphorylation and photosynthesis
七、电子传递与ATP合成的偶联机制（The chemiosmotic model was proposed to explain the coupling of electron flow and ATP synthesis） •★First proposed in 1961 by Peter Michell (a British). •★ Energy released from electron transferring is hypothesized to be first used to pump protons from the mitochondrial matrix to the intermembrane space (or from stroma to thylakoid lumen in chloroplasts), thus generating a proton gradient across the inner membrane; such a proton-motive force then drives ATP synthesis by moving protons back into the matrix via the ATP synthase-- The chemiosmotic model. •★ The model was initially opposed by virtually all researchers working in oxidative phosphorylation and photosynthesis