OXIDATIVE PHOSPHORYLATION AND ELECTRON TRANSPORT CHAIN (ETC) OXIDATIVE PHOSPHORYLATION Oxidative phosphorylation is the process in which ATP is formed as a result of the transfer of electrons from NADH or FADH 2 to O 2 by a series of electron carriers. This process, which takes place in mitochondria, is the major source of ATP in aerobic organisms. Oxidative phosphorylation is linked with the Electron transport chain (ETC). ELECTRON TRANSPORT CHAIN Electron transport chain (ETC) is the final common pathway in aerobic cells by which electrons derived from various substrates are transferred to Oxygen. The transfer of electrons from one electron carrier to the next releases energy, some of which is used to generate ATP from ADP through a process called Chemiosmosis. ETC is a series of highly organized Oxidation–Reduction reaction. In Eukaryotes, ETC takes place in the Mitochondria but in Prokaryotes, ETC takes place in Plasma membrane. Carrier Molecules in Electron Tra...