Question

What is the function of cytochrome C ?

Answer 1

Hint: Cytochromes are a type of protein which contains a haem group. They help in transport of electrons in the electron transport system in mitochondria and carry out redox reactions in the cells. Because of the presence of the haem group they are also called haem-proteins.

Complete answer:
International union of biochemistry and molecular biology (IUBMB) have classified the cytochrome into four types which are cytochrome a, cytochrome b, cytochrome c, and cytochrome d. Out of these cytochromes’ cytochrome c is a water-soluble substance. It is loosely attached to the inner membrane of mitochondria. It contains an iron metal centre which helps it in the electron transport chain.
Electron transport chain is made up of different compounds which help in oxidative phosphorylation in case of aerobic respiration producing large amounts of ATP. The whole transport process is carried out by a series of redox reactions. The ETC is made up of four complexes which are complex I, II, III, IV. These complexes are made up of proteins. Transport of electrons occurs from complex I to complex IV through different molecules.

Cytochrome c is a movable electron carrier which helps in the transfer of electrons from complex III to complex IV. Cytochrome c accepts electrons from complex III where ubiquinone acts as an electron donor. Then it moves to the complex IV and cytochrome c undergoes through oxidation, releasing the electron into it.

Note:-
ATP is known as the currency of energy which acts as a fuel for the working of the cell. Cytochrome c plays an important role in the ETC without which ATP would not be produced. Due to the presence of the haem group at its centre it could carry out different redox reactions causing transport of electrons.