Cytochrome c oxidase

<p>The <a href="/facts/Enzyme/DSI1Fh7y">enzyme</a> cytochrome c oxidase or Complex IV (was <a href="/facts/Enzyme_Commission_number/Y5GNLRKX">EC</a> <a href="https://enzyme.expasy.org/EC/1.9.3.1">1.9.3.1</a>, now reclassified as a translocase <a href="https://www.enzyme-database.org/query.php?name=EC+7.1.1.9&search=search_all&display=show_all&order=ec_num&nr=50">EC 7.1.1.9</a>) is a large <a href="/facts/Transmembrane_protein/0vQH5HrM">transmembrane protein</a> complex found in <a href="/facts/Bacteria/wC8xSCsU">bacteria</a>, <a href="/facts/Archaea/Adxh0aHw">archaea</a>, and the <a href="/facts/Mitochondria/ErHqrdJ1">mitochondria</a> of <a href="/facts/Eukaryotes/SkwyPLMA">eukaryotes</a>.
</p><p>It is the last enzyme in the <a href="/facts/Cellular_respiration/kb6gpsvL">respiratory</a> <a href="/facts/Electron_transport_chain/QjcIkgeR">electron transport chain</a> of <a href="/facts/Cell_(biology)/bLM9UQvy">cells</a> located in the <a href="/facts/Membrane/FDlaJe23">membrane</a>. It receives an electron from each of four <a href="/facts/Cytochrome_c/8gXbxw9z">cytochrome c</a> molecules and transfers them to one <a href="/facts/Oxygen/acyn6o8r">oxygen</a> molecule and four <a href="/facts/Proton/clCjepXP">protons</a>, producing two molecules of water. In addition to binding the four protons from the inner aqueous phase, it transports another four protons across the membrane, increasing the transmembrane difference of proton <a href="/facts/Electrochemical_potential/UpMRy1qq">electrochemical potential</a>, which the <a href="/facts/ATP_synthase/5NBMxsVX">ATP synthase</a> then uses to synthesize <a href="/facts/Adenosine_triphosphate/nB9bwgcU">ATP</a>.
</p>

Cytochrome c oxidase open-in-new

Cytochrome c oxidase