= Cytochrome
A <cytochrome> is a <protein> containing a <haem> group whose <iron> can change oxidation state during <electron transfer>. The surrounding <protein> tunes the properties of the <haem> and its interactions with electron donors and acceptors. The name denotes a broad biochemical class, not one unique <enzyme> or one universal reaction. <Molecular Biology of the Cell, 4th edition by Bruce Alberts and others>[Chapter 14, Electron-Transport Chains and Their Proton Pumps: heme-containing cytochromes]{ref}
For example, <cytochrome c> is a mobile carrier between respiratory complexes, while <cytochrome c oxidase> is a larger terminal complex that transfers <electrons> toward <oxygen>. Carrying an <electron> and pumping <protons> are distinct operations; not every individual <cytochrome> performs both. Spectral changes accompanying oxidation and reduction make these cofactors experimentally useful reporters of electron-transfer state.
Back to article page
