CMB 311 Study Guide - Glycogen Phosphorylase, Glycogen Synthase, Phosphorylase
Document Summary
Glycogen is made in animals, but starch is made in plants. Similar to amylopectin (starch) but glycogen has many more branch points. Only one reducing end, attached to glycogenin (protein) What molecule does the reaction catalyzed by glycogen phosphorylase release? (product) Glycogen is broken down by glycogenolysis, its major enzyme is glycogen phosphorylase. Glycogen phosphorylase cleaves by the addition of orthophosphate to yield glucose 1-phosphate. Phosphorylase catalyzes the sequential removal of glucosyl residue. The cleavage bond is referred to as phosphorylase. What do transferase and debranching enzymes do? (brief) Transferase shifts a block of 3 glucosyl residues from one outer branch to another. Transfer exposes a single glycosyl residue joined by an alpha-1,6-glycosidic linkage (debranching enzyme) Free glucose molecule is released as a result. Once glucose 1-phosphate is released from glycogen, it is converted to glucose. No atp needed in the above reaction - it is saved for glycolysis.
