foszforilálása

Foszforilálás is the addition of a phosphate group (PO4) to a molecule. This process is a fundamental biochemical reaction that occurs in virtually all living organisms. It plays a crucial role in numerous cellular processes, including energy metabolism, signal transduction, and the regulation of enzyme activity.

In cellular respiration, the primary way cells generate energy is through a series of phosphorylation reactions. Adenosine diphosphate (ADP) is phosphorylated to adenosine triphosphate (ATP), the main energy currency of the cell. This phosphorylation can occur through substrate-level phosphorylation, where a phosphate group is directly transferred from a high-energy substrate molecule to ADP, or through oxidative phosphorylation, which involves a series of electron transfer reactions and a proton gradient. Photophosphorylation is another type of phosphorylation that occurs during photosynthesis, where light energy is used to synthesize ATP.

Beyond energy production, phosphorylation is a key mechanism for regulating protein function. Many enzymes and structural proteins are activated or inactivated by the addition or removal of phosphate groups. This reversible modification, often catalyzed by kinases (which add phosphate groups) and phosphatases (which remove them), acts as a molecular switch, allowing cells to respond dynamically to internal and external signals. Phosphorylation is central to signal transduction pathways, where a cascade of phosphorylation events transmits information within and between cells, ultimately leading to specific cellular responses.