The electron transport chain in the mitochondrion is the site of oxidative phosphorylation in eukaryotes. The NADH and succinate generated in the citric acid cycle is oxidized, releasing energy to power the ATP synthase.
الفسفرة التأكسدية Oxidative phosphorylation هو عبارة عن مسار استقلابي metabolic pathway يستخدم الطاقة الناتجة عن الأكسدة للمواد الغذائية لإنتاج آ.تي.بي. مع ان كافة أشكال الحياة على الأرض تستخدم مجالا وساعا من المغذيات المختلفة ، فإن الجميع يقوم بإجراء فسفرة تأكسدية إنتاج الآ تي بي ، الجزيئة الحاملة للطاقة من عملية الاستقلاب. يعتبر هذا المسار فعالا جدا لتخخزين الطاقة إذا ما قورن بعمليات التخمير fermentation الحيوية البديلة كما في حالة تحلل الغليكوز glycolysis
فهرس
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مثبطات
| Compounds | Use | Effect on oxidative phosphorylation |
|---|---|---|
| Cyanide Carbon monoxide |
Poisons | Inhibit the electron transport chain by binding more strongly than oxygen to the Fe–Cu center in cytochrome c oxidase, preventing the reduction of oxygen.[1] |
| Oligomycin | Antibiotic | Inhibits ATP synthase by blocking the flow of protons through the Fo subunit.[2] |
| CCCP 2,4-Dinitrophenol |
Poisons | Ionophores that disrupt the proton gradient by carrying protons across the membrane. This uncouples proton pumping from ATP synthesis.[3] |
| Rotenone | Pesticide | Prevents the transfer of electrons from complex I to ubiquinone by blocking to the ubiquinone-binding site.[4] |
مراجع
- ^ Tsubaki M (1993). "Fourier-transform infrared study of cyanide binding to the Fea3-CuB binuclear site of bovine heart cytochrome c oxidase: implication of the redox-linked conformational change at the binuclear site". Biochemistry 32 (1): 164–73.
- ^ Joshi S, Huang YG (1991). "ATP synthase complex from bovine heart mitochondria: the oligomycin sensitivity conferring protein is essential for dicyclohexyl carbodiimide-sensitive ATPase". Biochim. Biophys. Acta 1067 (2): 255–8.
- ^ Heytler PG (1979). "Uncouplers of oxidative phosphorylation". Meth. Enzymol. 55: 462–42.
- ^ Lambert AJ, Brand MD (2004). "Inhibitors of the quinone-binding site allow rapid superoxide production from mitochondrial NADH:ubiquinone oxidoreductase (complex I)". J. Biol. Chem. 279 (38): 39414–20.
قراءات أخرى
Introductory
- Nelson DL; Cox MM (2004). Lehninger Principles of Biochemistry، 4th ed، W. H. Freeman. ISBN 0-716-74339-6.
- Schneider ED; Sagan D (2006). Into the Cool: Energy Flow, Thermodynamics and Life، 1st ed، University of Chicago Press. ISBN 0-226-73937-6.
Advanced
- Nicholls DG; Ferguson SJ (2002). Bioenergetics 3، 1st ed، Academic Press. ISBN 0-125-18121-3.
- Haynie D (2001). Biological Thermodynamics، 1st ed، Cambridge University Press. ISBN 0-521-79549-4.
- Rajan SS (2003). Introduction to Bioenergetics، 1st ed، Anmol. ISBN 8-126-11364-2.
- Wikstrom M (Ed) (2005). Biophysical and Structural Aspects of Bioenergetics، 1st ed، Royal Society of Chemistry. ISBN 0-854-04346-2.
وصلات خارجية
General resources
- Animated diagrams illustrating oxidative phosphorylation Wiley and Co Concepts in Biochemistry
- Oxidative phosphorylation Metabolic Pathways of Biochemistry, the online reference of metabolism for students and teachers, at George Washington University
- ATP synthase - the rotary engine in the cell Brief introduction, including videos of microscope images of the enzyme rotating, at Tokyo Institute of Technology
- On-line biophysics lectures Antony Crofts, University of Illinois at Urbana-Champaign
Structural resources
- Animations of the ATP synthase Hongyun Wang and George Oster, University of California, Berkeley
- PDB molecule of the month:
- Interactive molecular models at Universidade Fernando Pessoa:
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|---|---|
| Complex I - Complex II - Coenzyme Q - Complex III - Cytochrome c - Complex IV - Alternative oxidase - Electron-transferring-flavoprotein dehydrogenase |
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| تنفس هوائي | تحلل الغليكوز ← نزع كربوكسيل البيروفات ← دورة حمض الليمون ← فسفرة تأكسدية (سلسلة نقل الإلكترون + تخليق ال ATP) |
| تنفس لاهوائي | تحلل الغليكوز ← Lactic Acid Formation أو Ethanol Formation |