| Cytochrome C Oxidase |
Article Index for Cytochrome C |
Information AboutCytochrome C Oxidase |
| CATEGORIES ABOUT CYTOCHROME C OXIDASE | |
| cellular respiration | |
| ec 1.9.3 | |
| hemoproteins | |
| integral membrane proteins | |
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The Enzyme cytochrome c oxidase (, ) is a large transmembrane Protein found in the Mitochondrion and is the terminal electron acceptor in the Electron Transport Chain (complex IV), taking 4 reducing equivalents from Cytochrome C and converting molecular Oxygen to water. In the process, it translocates protons, helping to establish a Chemiosmotic Potential that the ATP Synthase then uses to synthesize ATP . Summary reaction: 4 Fe+2-cytochrome c + 4H+ + O2 → 4 Fe+3-cytochrome c + 2 H2O. The complex is a large Lipoprotein composed of several Metal prosthetic sites and 13 protein subunits. In mammals, 10 subunits are nuclear in origin and 3 are synthesized mitochondrially. The complex contains 2 Cytochrome s, the a and a3 cytochromes, and two Copper centers, the CuA and CuB centers. In fact, the cytochrome a3 and CuB are a binuclear center that is the site of oxygen reduction. The mechanism of action of this large complex is still an active research topic. Cyanide , Carbon Monoxide and Azide all bind irreversibly to Cytochrome c Oxidase. The protein is then inhibited from functioning, causing chemical Suffocation . EXTERNAL LINKS
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