citokróm

Cytochrome is a general term for a group of heme-containing proteins found in the inner mitochondrial membrane and also in the endoplasmic reticulum and chloroplasts. These proteins play a crucial role in cellular respiration and photosynthesis. The heme group, which contains an iron atom, is the site of electron transfer. Cytochromes are involved in the electron transport chain, a series of protein complexes that transfer electrons from one molecule to another. This process generates a proton gradient that is used to produce ATP, the main energy currency of the cell. Different types of cytochromes are classified based on their absorption spectra and the structure of their heme groups, such as cytochromes a, b, c, and d. They are also involved in various metabolic processes, including the detoxification of drugs and other foreign compounds by enzymes like the cytochrome P450 family. The iron atom within the heme group can readily switch between its oxidized (ferric, Fe3+) and reduced (ferrous, Fe2+) states, which is essential for its function as an electron carrier.