Cellular oxidative phosphorylation is important biochemical processes, the final cell respiration pathway, glycolysis and Krebs cycle located after the main steps of "energy currency" atp generation. This process can be seen as coupled electron transfer adp phosphorylation generated atp. Oxidative phosphorylation occurs in the cell membrane of prokaryotes or eukaryotes mitochondrial inner membrane. The process consists of two parts: the electron transport chain and atp synthase. Nadh and fadh2 former glycolysis and Krebs cycle generated by the oxidation, while the cell membrane or proton pump mitochondrial inner membrane proton gradient generated; latter, also known as composite v, using the proton gradient of protons due to the flow The adp and synthetic phosphoric acid as atp, which will produce hydrogen peroxide carrier in the form of energy saved atp's. Generating calculated atp So far, the number of protons in the proton-electron transfer chain molecule or fadh2 nadh pump out the oxidation and enzymatic synthesis of a synthetic atp atp desired still are unknown, and molecular oxygen is reduced to half (equivalent to a atp nadh fadh2 or oxidized) is generated when called p / o value. In this regard, there are many experiments trying to calculate these two values, but have not yet achieved consensus. For the electron transport chain, the most accepted conclusion is an oxidized nadh proton pump 10, a pump is oxidized fadh2 6. The synthetic molecule atp approximately within four protons. Then for nadh, p / o value of about 2.5, while fadh2 the p / o value of about 1.5. But also some textbooks considered p / o values were 3 and 2.
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氧化磷酸化
氧化磷酸化
氧化磷酸化
Concept and oxidative phosphorylation coupling portions
氧化磷酸化的概念和偶联部位
氧化磷酸化的概念和偶联部位
氧化磷酸化的概念和偶联部位
氧化磷酸化的概念和偶联部位
氧化磷酸化的概念和偶联部位
A concept: oxidative phosphorylation (oxidative phosphorylation) is the generation of ATP accompanied role in biological oxidation. There are two types of phosphorylated and phosphorylated metabolites in the respiratory chain connected connection. There are two ways that generate ATP. A metabolite is the dehydrogenation of intramolecular energy redistribution of the inorganic phosphate to form a first intermediate energy metabolites induce becomes ADP ATP. This is known as substrate level phosphorylation. Such as 3 - glyceraldehyde phosphate oxidation of 1,3 - diphosphoglycerate, then the degradation of 3 - phosphoglycerate. The other is coupled to the formation of ATP in the respiratory electron transfer chain. 95% of ATP in vivo from this approach. Two coupling parts: The experimentally determined relationship between the number of generation and consumption of oxygen and ATP calculated between redox reaction ΔGO 'and the relationship between the electrode potential difference ΔE can be proved. P / O ratio is the metabolite per consumed inorganic oxide to 1 mol of phosphorus atom of oxygen consumed by the number of moles, the number of moles of ATP synthesis. Experiments show that, NADH in the respiratory chain is oxidized to water P / O value approximately equal to 3, which generates 3 molecules of ATP; FADH2 oxidation of P / O value approximately equal to 2, which generates two molecules of ATP. Oxygen - also potential changes along the respiratory chain is a measure of the free energy change per step. According ΔGO '= - nFΔE O' (n is the number of electron transfer, F is the Faraday constant), Q segment from NADH to the potential difference of approximately 0.36V, from Q to Cytc to 0.21V, molecular oxygen from aa3 to 0.53V, calculated the corresponding ΔGO 'were 69.5,40.5,102.3 kJ / mol. So generally considered part of the following three parts of the ATP is generated in the electron transport chain. NADH → NADH dehydrogenase → ‖ Q → → cytochrome bc1 complex ‖ ‖ Cytc → aa3 → O2
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Oxidation of cytosolic NADH
氧化磷酸化 胞液中NADH的氧化
氧化磷酸化 胞液中NADH的氧化
氧化磷酸化 胞液中NADH的氧化
氧化磷酸化 胞液中NADH的氧化
Glucose metabolism in the Krebs cycle and fatty acid β-oxidation generates NADH (reducing equivalents) in the mitochondria, available immediately through the electron transport chain, oxidative phosphorylation. NADH produced in the cytoplasm of the cell, will have as NADH generated by glycolysis shuttle system (shuttle system) so that hydrogen enters the mitochondrial NADH oxidation. (A) α-glycerophosphate shuttle role This effect is mainly present in brain, skeletal muscle, the carrier is α-glycerophosphate. Cytosolic NADH under the catalysis of α-glycerol phosphate dehydrogenase, that reduction of dihydroxyacetone phosphate, α-glycerol phosphate, which through the inner mitochondrial membrane, and is α-glycerophosphate dehydrogenase on the endometrium ( to FAD prosthetic group) catalytic regenerate dihydroxyacetone phosphate and FADH2, which enters the respiratory chain succinate oxidation. Glucose in these tissues is completely oxidized ATP less than other organizations, a mole G → 36 mol ATP. (B) malate - aspartate shuttle role Mainly in the liver and myocardium. 1 mole of G → 38 mol ATP The cytosolic malate dehydrogenase, NADH in the catalyzed reduction of oxaloacetate that malic acid, α-ketoglutaric acid vector into the latter by means of the inner membrane of mitochondria, and in the mitochondrial malate dehydrogenase regenerate oxaloacetate and NADH catalyzed. NADH oxidation of NADH into the respiratory chain, generating 3 molecule ATP. Oxaloacetate catalyzed by aspartate aminotransferase generate aspartic acid, which is then transported by the carrier acidic amino acids into the mitochondria oxaloacetate.
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Oxidative phosphorylation coupling mechanism
氧化磷酸化偶联机制
氧化磷酸化偶联机制
氧化磷酸化偶联机制
氧化磷酸化偶联机制
氧化磷酸化偶联机制
(A) chemical permeation hypothesis (chemiosmotic hypothesis) In 1961, the British scholar Peter Mitchell proposed chemical permeation hypothesis (1978 Nobel Prize in Chemistry), indicating that the electron transfer energy released is used to form a proton gradient across the inner mitochondrial membrane (H + gradient), the gradient driving ATP synthesis. This process is summarized as follows: Oxidation 1.NADH, passing along the electron respiratory chain, resulting in H + H + pump are three, namely NADH dehydrogenase, cytochrome bc1 complex and cytochrome oxidase pumped across the membrane of endometrial gap from the mitochondrial matrix. 2.H + pump, generates a high concentration of H + in the gap film, not only the outer side than the pH inside the membrane is low (pH gradient is formed), so that the original outer positive and negative transmembrane potential within increased, thereby forming Be the electrochemical proton gradient proton motive force, and the film is the sum of the chemical potential gradient of H +. 3.H + flow back to the mitochondrial matrix through ATP synthase, ATP synthase proton motive force driving the synthesis of ATP. (B) ATP synthase ATP synthase consists of two parts (Fo-F1), a spherical head portion protruding toward the substrate liquid F1 soluble. Subunit is buried in the bottom of the endometrium Fo, hydrophobic proteins, constituting H + channels. Under physiological conditions, H + to flow only from the outside of the substrate film, the channel switching by adjusting the handle of a protein.
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影响氧化磷酸化的因素
影响氧化磷酸化的因素
影响氧化磷酸化的因素
Cyanide, CO, azide (N3-) inhibition of cytochrome oxidase. On electron transport and ADP phosphorylation was inhibited by substances called oxidative phosphorylation inhibitors such as oligomycin. (Two) uncoupler
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Wikipedia Encyclopedia
氧化磷酸化 百科大全
Oxidative phosphorylation Material oxidation and ADP phosphorylation coupling process. When the biological oxidation in mitochondria, substrates under desaturase off the hydrogen breath hydrogen delivery system through transfer of oxygen to produce water stepwise process, oxygen consumption, the consumption of inorganic phosphate, generating high-energy phosphate bond that ADP phosphorylated ATP.
