Cytochrome c

Cytochrome c, or cyt c (horse heart: PDB 1HRC) is a small heme protein found loosely associated with the inner membrane of the mitochondrion. It is a soluble protein, unlike other cytochromes, and is an essential component of the electron transfer chain. It is capable of undergoing oxidation and reduction, but does not bind oxygen. It transfers electrons between Complexes III and IV.