glukoosi1phosphate

Glucose-1-phosphate is a glucose molecule in which a phosphate group is esterified to the anomeric carbon (C1). It functions as an important intermediate in carbohydrate metabolism in a variety of organisms, including animals, plants, and bacteria.

Formation and metabolic roles: In glycogenolysis, glycogen phosphorylase cleaves glycogen to release glucose-1-phosphate from non-reducing ends, in the presence of inorganic phosphate. Glucose-1-phosphate can be converted to glucose-6-phosphate by the action of phosphoglucomutase, providing a route into glycolysis, gluconeogenesis, or the pentose phosphate pathway. The interconversion between glucose-1-phosphate and glucose-6-phosphate is reversible, and in many pathways glucose-1-phosphate serves as a gateway between storage polysaccharides and central carbon metabolism.

Activation and biosynthesis: Glucose-1-phosphate can be activated to UDP-glucose by UDP-glucose pyrophosphorylase, using UTP as the energy source. UDP-glucose is a key activated sugar donor for glycogen synthesis and for the biosynthesis of other polysaccharides and glycoproteins in various organisms. This activation step links energy status and nucleotide availability to carbohydrate assembly processes.

Biological context: G1P is a central metabolite that connects glycogen breakdown with broader metabolic pathways. Its levels influence glycogen turnover and carbon flux, and enzymes that manage G1P, such as glycogen phosphorylase and phosphoglucomutase, play crucial roles in energy balance. In bacteria, G1P-derived UDP-glucose also contributes to cell wall and extracellular polysaccharide biosynthesis.

See also: glycogenolysis, phosphoglucomutase, UDP-glucose pyrophosphorylase.