Cytochromes may be defined as the the proteins that are required for the process of electron transport chain. These cytochromes molecules helps the oxidation, reduction and transfer of electrons during the electron transport chain.
Aerobic organisms has nearly equal identical structure in all organism. All organism that contains cytochromes has heme as a cofactor. Ring system of cytochrome is present with iron as the main element in almost all organism. These cytochromes shows the conserved sequences that are common to almost all the organism that contain cytochrome molecule.
Cytochromes:- They are iron containing hemoproteins that serve many cellular functions including energy production, steroid biosynthesis, and degradation of toxins.
Cytochromes occur in all organisms except a few obligate anaerobes. They are structurally similar among organisms. These are proteins to which one to two tetrapyrrole rings are bound. These tetrapyrroles are very similar to the chromophores of chlorophylls in plants. However, chlorophylls(in plants) contain Mg++ as the central atom in the tetrapyrrole, whereas the cytochromes(in aerobic animals) have an iron atom (Figure).
