ADP-Glucose (ADPG) is an immediate precursor used in the biosynthesis, by glucose addition, of storage polysaccharides in plants, green algae, and cyanobacteria, as well as structural polysaccharides in certain bacteria. It is used by amylose synthases or starch synthases in plastids in the production of amylose, amylopectins, starch, and other polysaccharides. ADPG is normally generated within plastids, although it can be biosynthesized in the cytoplasm of certain grasses and imported into plastids by a membrane-bound transporter.
Adenosine-5′-diphosphoglucose (ADP-Glucose) is a substrate widely used as a glucose donor. It is a substrate starch synthase (EC 2.4.1.21) in starch synthesis. ADP-glucose is a substrate for α-1,4-glucan-protein synthase (ADP-forming) (EC 2.4.1.113), ADP-glucose pyrophosphorylases and many glucosyltransferases.