What is oxidative phosphorylation?

Oxidative phosphorylation is a crucial metabolic process that occurs in the mitochondria of eukaryotic cells, where the energy produced from the transfer of electrons through the electron transport chain is used to generate adenosine triphosphate (ATP). This process begins after glycolysis and the Krebs cycle, which produce electron carriers (NADH and FADH2). These carriers then donate electrons to the electron transport chain, leading to a series of redox reactions that ultimately result in the pumping of protons (H+) across the mitochondrial membrane.

The energy from the electrons moving through the chain creates an electrochemical gradient, often referred to as the proton motive force. This gradient drives protons back across the membrane through ATP synthase, a protein complex that catalyzes the conversion of adenosine diphosphate (ADP) and inorganic phosphate (Pi) into ATP. This entire process is what defines oxidative phosphorylation, highlighting its role in energy production.

Understanding why this process is not confined to plants, not a type of fermentation, and unrelated to DNA synthesis helps clarify its significance in cellular respiration. Fermentation occurs in anaerobic conditions and does not involve oxidative phosphorylation, while DNA synthesis pertains to cellular replication, making it distinct from