the sequence of reactions by which most living cells generate energy during the process of aerobic respiration. It takes place in the mitochondria, consuming oxygen, producing carbon dioxide and water as waste products, and converting ADP to energy-rich ATP.
An electron transport chain couples electron transfer between an electron donor and an electron acceptor with the transfer of H+ ions across a membrane. The resulting electrochemical proton gradient is used to generate chemical energy in the form of adenosine triphosphate. .