Cytochromes are a group of heme-containing proteins found in various organisms, including plants, animals, and bacteria. They play a crucial role in the electron transport chain, a series of reactions that generate energy in the form of ATP during cellular respiration. Cytochromes facilitate the transfer of electrons, helping to convert energy from nutrients into a usable form. These proteins are characterized by their ability to undergo oxidation and reduction, allowing them to participate in redox reactions. Different types of cytochromes, such as cytochrome c and cytochrome P450, have specific functions, including detoxification and metabolism of drugs and other compounds.