has part has part has_part cytochrome-c oxidase activity https://github.com/geneontology/go-ontology/issues/20924 https://github.com/geneontology/go-ontology/issues/21275 https://github.com/geneontology/go-ontology/issues/30272 cytochrome oxidase activity Catalysis of the reaction: 4 Fe(II)-[cytochrome c] + O2 + 8 H+(in) = 4 Fe(III)-[cytochrome c] + 2 H2O + 4 H+(out). MetaCyc:CYTOCHROME-C-OXIDASE-RXN cytochrome c oxidase activity indophenolase indophenol oxidase Reactome:R-HSA-163214 RHEA:11436 cbb3-type cytochrome c oxidase ba3-type cytochrome c oxidase cytochrome a3 activity The reduction of O2 to water is accompanied by the extrusion of four protons from the intramitochondrial compartment. EC:7.1.1.9 GO:0004129 Warburg's respiratory enzyme activity caa3-type cytochrome c oxidase aa3-type cytochrome c oxidase complex IV (mitochondrial electron transport) activity molecular_function cytochrome aa3 activity electron transfer activity proton transmembrane transporter activity oxidoreduction-driven active transmembrane transporter activity oxidoreductase activity, acting on a heme group of donors active monoatomic ion transmembrane transporter activity