Describe the key events that occur during the process of oxidative phosphorylation, remarking on the net energy gained by such reactions.
Both the anaerobic and aerobic stages of the breakdown of glucose yield the energy-rich compound NADre. In fact, it is the transfer of this compound's electrons to oxygen via the respiratory electron-transport chain that yields most of the ATP generated from the degradation of a molecule of glucose. During a process called oxidative phosphorylation, NADre and FADre molecules are oxidized, releasing energy that is then used to phosphorylate ADP into ATP. The energy is released as NADre and FADre give up high-energy electrons, along with hydrogen atoms, to oxygen to form water. In between the points at which the NADre and FADre give up their electrons and oxygen accepts them, the electrons are passed down a chain of electron-transport compounds. As the electrons pass down the chain, they give up their energy to ADP molecules. The electrons from the eight NADre molecules produced during aerobic respiration pass down the whole chain; these electrons release energy at three points, producing three ATP each. The electrons from the two NADre produced during glycolysis and the two FADre pass down only part of the chain; these electrons release
