Dr. Prabhakar Singh SEM-III_Gycogen Metabolism

1. Glycogen Metabolism
1. Glycogenesis
2. Glycogenolysis
3. Regulation Of Glycogen Metabolism
4. Glycogen Storage Disease

2. GLYCOGENESIS
1- Synthesis of UDP-glucose
2-Glycogen synthesis by glycogen synthase
3-Formation of branches in glycogen

3. 1- Synthesis of UDP-glucose

4. 2-Glycogen synthesis by Glycogensynthase

5. 3- Formation of branches in glycogen
amylo-(1,4 S 1,6)-transglycosylase

6. Glycogen Breakdown
A. Glycogen Phosphorylase
B. Phosphoglucomutase
C. Glycogen Debranching Enzyme
Gycogenolysis

7. • Glycogen phosphorylase is a dimer of identical 842-residue (97-kD) subunits
that catalyzes the controlling step in glycogen breakdown.
• It is regulated both by allosteric interactions and by covalent modification.
• The enzyme-catalyzed modification/demodification process yields two forms of
phosphorylase: phosphorylase a, which has a phosphoryl group esterified
to Ser 14 in each of its subunits, and phosphorylase b, which lacks these
phosphoryl groups.
1- Glycogen Phosphorylase

8. 2. Phosphoglucomutase

9. Glycogen Debranching Enzyme

10. REGULATION OF GLYCOGEN METABOLISM
1. Allosteric Regulation

11. 2- Hormonal Regulation

12. 3- Regulation by Ca++

13. GLYCOGEN STORAGE DISEASES