Glycogen phosphorylase is an enzyme that catalyzes the reaction: glycogen(n) + inorganic phosphate -> glycogen(n-1) + glucose-1-phosphate
The release of glucose provides the substrate for a number of pathways e.g. glycolysis or glucose release to the blood. Since enzymes further down these pathways are unsaturated, the activity of glycogen phosphorylase is important in determining the amount of activity through an entire pathway - it is flux-generating. Consequently, it is under precise control by a number of regulatory molecules.
Glycogen synthase catalyzes the reverse reaction during glycogenesis. The interaction between both enzymes is considered in the submenu.
Last reviewed 01/2018