Cytochromes (Gr. Kitos - Cell, Chroma - Color)

Cytochromes (Gr. Kitos - Cell, Chroma - Color)

Cytochromes are iron-containing hemoproteins in the electron transport system, which are alternately oxidized and reduced during cellular respiration.

Cytochromes play an important role in the processes of redox reactions in living cells. They are localized in mitochondria, chloroplasts and bacterial membranes. Cytochromes consist of the protein apocytochrome and the prosthetic group heme. Heme contains iron ion, which determines the ability of cytochromes to undergo reversible oxidation-reduction.

During the respiratory chain of electron transfer, cytochromes accept electrons from other components of this chain (for example, from NADH), giving them further to subsequent acceptors (for example, molecular oxygen). Thus, a gradual transfer of electrons occurs from the reduced substrates to the final acceptor with the release of energy for the synthesis of ATP.