Glukozo1fosforanu

Glukozo-1-fosforanu, also known as glucose-1-phosphate (G1P), is a phosphorylated derivative of glucose in which a phosphate group is esterified to the C-1 hydroxyl. It is a hexose phosphate that can exist in alpha- or beta-anomeric forms and typically adopts a pyranose ring in solution.

G1P is a key metabolic intermediate in carbohydrate metabolism. During glycogenolysis, glycogen phosphorylase cleaves glucose units from glycogen with inorganic phosphate, yielding glucose-1-phosphate. In mammals, phosphoglucomutase rapidly converts G1P to glucose-6-phosphate (G6P), which can enter glycolysis, feed the pentose phosphate pathway, or be dephosphorylated to free glucose in the liver. In plants, G1P serves as a branch point for starch biosynthesis via the ADP-glucose pathway.

Biosynthesis and utilization extend beyond energy production. G1P participates in the formation of UDP-glucose through the reaction with UTP, catalyzed by UDP-glucose pyrophosphorylase, producing UDP-glucose and inorganic pyrophosphate. UDP-glucose acts as a donor of glucose residues for glycogen and cellulose synthesis and for glycoprotein and glycolipid biosynthesis. In plants, G1P is a substrate for ADP-glucose pyrophosphorylase, forming ADP-glucose, the glucosyl donor for starch biosynthesis.

Overall, glucose-1-phosphate links storage carbohydrate breakdown with central metabolism and biosynthetic pathways, serving as a pivotal intermediate that channels carbon into energy production, polysaccharide synthesis, and nucleotide-sugar formation.