Glycogenolysis
Unlike glycogenesis, glycogenolysis is the breakdown of glycogen. Glycogen is broken down in the liver and muscle catalysed by the enzyme glycogen phosphorylase. Inorganic phosphate (Pi) is used for the lysis and hence is called phosphorolysis. Phosphorylase specifically acts upon a 1 →4 linkage of glycogen to produce glucose-1- phosphate. The removal of al,4 glucosyl residues continues until about 4 glucose residues remain on either side of a-1,6 branch, then the debranching enzyme (amylo a 1,6 glucosidase) causes the hydrolytic splitting of a 1,6 linkages. Here free glucose is formed (since no phosphate is used for lysis).