UDPglukoosipyr

UDPglukoosipyr is a pyranose form of UDP-glucose, a vital molecule in cellular metabolism. UDP-glucose, also known as uridine diphosphate glucose, is a nucleoside diphosphate sugar consisting of glucose and uridine diphosphate. The "pyr" designation specifically refers to the cyclic, six-membered ring structure of the glucose molecule, which is the most common form of glucose found in biological systems.

This compound serves as a key intermediate in carbohydrate metabolism, particularly in the synthesis of glycogen, sucrose, and other polysaccharides. In glycogen synthesis, UDP-glucose is the direct precursor, with glycogen synthase catalyzing its addition to the growing glycogen chain. Similarly, in plants, UDP-glucose is the substrate for sucrose synthase, which is involved in the production of sucrose, a major transport sugar.

UDPglukoosipyr is synthesized from glucose-1-phosphate and UTP (uridine triphosphate) by the enzyme UDP-glucose pyrophosphorylase. This reaction is an example of substrate-level phosphorylation, generating UDP-glucose and pyrophosphate. The breakdown of UDP-glucose releases UDP and glucose, which can then re-enter metabolic pathways. Its widespread role makes UDPglukoosipyr fundamental for energy storage and structural polysaccharide formation in a vast array of organisms.