Question

What is oxidative phosphorylation?

Answer 1

Hint: Oxidative phosphorylation is also called electron transport – linked phosphorylation. Its end product is ATP. In addition, it is a part of the cellular respiration process.

Complete answer: Metabolic pathway in which cells use enzymes to oxidize nutrients, thereby releasing the chemical energy stored within in order to produce adenosine triphosphate (ATP) is called oxidative phosphorylation. This process takes place inside the mitochondria of the cell. Oxidative phosphorylation is carried out by almost all aerobic organisms. During the process of oxidative phosphorylation, the transfer of electrons takes place from electron donors to electron acceptors such as oxygen in redox reactions. Energy stored in the relatively weak double bond of oxygen is released during the process of redox reaction which is used to form ATP. A series of protein complexes catalyze these redox reactions within the inner membrane of the mitochondria in eukaryotes. In prokaryotes, these protein complexes are located in the cell's intermembrane space. Adenosine diphosphate (ADP) is converted into adenosine triphosphate using enzyme ATP synthase in a phosphorylation reaction. ATP synthase is also called complex V. It is the final enzyme used in the process of oxidative phosphorylation. Three ATPs are produced by oxidation of one NADH through the process of electron transfer chain.

Note: About $$42$$ of energy is conserved in the form of three ATPs by oxidizing one NADH and the remaining energy is lost as heat. Shortage in oxygen level likely alters ATP production rates as oxygen is essential for oxidative phosphorylation. The process of oxidative phosphorylation produces reactive oxygen species such as superoxide and hydrogen peroxide. These reactive oxygen species lead to the propagation of free radicals, damaging cells and contributing to disease and, possibly, aging.