|
The electron transfer chain (also called the electron transport chain, or simply electron transport), is a series of protein complexers and lipid messengers spanning the inner mitochondrial membrane that accepts electrons from electron donors such as NADH or succinate, shuttles these electrons from within the mitochondrial matrix across the inner mitochondrial membrane into the intermembrane space, creating an electrical and chemical gradient, and through the proton driven chemistry of the ATP synthase (aka the F0F1 particle), generates adenosine triphosphate (ATP).
There are five complexes normally associated with the electron transfer chain.
All of these are proteolipid complexes, with the first four containing either flavins, iron-sulfur clusters, copper centers, or heme moieties. Complexes I, III, and IV are proton pumps. Complex II is part of the Krebs cycle and does not pump protons, and Complex V uses the electrochemical potential generated to create ATP.
Complex IV is the terminus of the electron transfer chain, where oxygen from the lungs is reduced by electrons and hydrogen protons (provided by NADH and/or FADH2) to make water.
Cytochrome c is also an essential part of the electron transfer chain. It is a soluble protein loosely associated with the inner mitochondrial membrane, and transfers electrons between Complexes III and IV.
The electron transfer chain can be inhibited by various poisons. Among them we can cite carbon monoxide, cyanide, azide, antimycin, amytal and rotenone.
See also:
|
