Definition of Cytochrome-c oxidase

1. An enzyme,ferrocytochrome-c:dioxygen oxidoreductase, EC 1.9.3.1, cytochrome aa3. The major respiratory protein of animal and plant mitochondria, it catalyzes the oxidation of Fe(II)-cytochrome c, and the reduction of dioxygen to water. Contains two hemes and three copper atoms, arranged in three centers. Heme a3 and copper-B form a center that reacts with dioxygen;the second heme is cytochrome a; the third site, copper-A,is a dinuclear center.