Explain the process of oxidative phosphorylation

Oxidative phosphorylation is the process by which energy in the form of ATP is produced when there is oxygen present in the cells. It occurs in the membrane of the mitochondria. Reduced NAD which is produced in the Krebs cycle reaches the inner membrane and is split into a hydrogen and NAD, the NAD is recycled for use in glycolysis and the Krebs cycle. The hydrogen is split into a proton (H⁺ ) and an electron. The electron is passed through an electron transport chain in the inner membrane, down a decreasing energy gradient, releasing some energy at each point. The energy is used to actively pump the protons against their concentration gradient into the inter membrane space. As the concentration of protons in the inter membrane space increases an electrochemical gradient is set up which causes the protons to diffuse back into the mitochondria through a specialised transporter protein called ATPase. This process is chemiosmosis. The energy from this process is used to phosphorylation ADP to ATP. From one molecule of glucose, 32 ATP can be produced. The left over proton, combines with oxygen and electron to produce water. Another product of aerobic respiration.