Cytochrome c oxidase is the last enzyme in the respiratory electron transport chain of mitochondria and it is also called Complex IV. Cytochrome c oxidase receives an electron from each of four cytochrome c molecules, and transfers them to one oxygen molecule, converting molecular oxygen to two molecules of water. In higher plants mitochondria, Complex IV processes 14 subunits. COX 6A (AT4G37830) is one subunit of the Complex IV.
