glükóz6foszfatdehidrogenáz

Glükóz6foszfat, often abbreviated as G6P, is a vital molecule in cellular metabolism. It is a phosphorylated form of glucose, meaning a phosphate group has been attached to the sixth carbon atom of the glucose molecule. This phosphorylation is a critical first step in many metabolic pathways, trapping glucose within the cell and preparing it for further breakdown or storage.

The primary roles of G6P include its involvement in glycolysis, the process by which glucose is broken down to produce ATP, the cell's main energy currency. G6P is also a precursor for glycogen synthesis, the storage form of glucose in animals, and for the pentose phosphate pathway, which generates NADPH and precursors for nucleotide synthesis. In plants and some bacteria, G6P is also a key intermediate in photosynthesis and the synthesis of cell wall components.

The conversion of glucose to G6P is catalyzed by enzymes called hexokinases (in most tissues) or glucokinase (primarily in the liver and pancreatic beta cells). This reaction requires ATP. The specific enzyme used and its regulatory properties influence how glucose is processed by different cell types. The concentration of G6P within a cell is a sensitive indicator of the cell's energy status and glucose availability, playing a regulatory role in various metabolic processes.