5 Written questions
5 Matching questions
- What irreversible reaction drives the synthesis of UDP-glucose?
- What role does UDP-glucose play in Glycogen synthesis?
- What converts Glucose 6 phosphate into glucose in liver?
- What does transferase do?
- Why is branching important in glycogen synthesis?
- a PPi+ H2O=> 2Pi
- b Transferase transfers the 3 terminal glucose residues from outer branch to the center, main linear branch
- c Glycogen synthesis involves transfer of glucose from UDP-glucose to a growing chain
- d Increases the number of terminal glucose residues which are site of action for glycogen phosphorylase and synthase. Branching increases rate of glycogen synthesis and degradation
- e Glucose 6 phosphatase converts Glucose 6 phosphate into glucose for export out of the liver and transport to other tissues
5 Multiple choice questions
- Glycogen phosphorylase, Transferase, alpha 1,6 glucosidase, phosphoglucomutase
- Glycogen (n residues) + Pi=> glucose-1-phosphate + Glycogen (n-1 residues)
- Must be at least 4 residues away from other branches. Links are alpha 1,6 glycosidic bond
- Glycogen synthase catalyzes transfer of glucose from UDP-glucose to a growing chain
- Alpha 1,6 glucosiase hydrolyzes the alpha 1,6 glucosidic bond to release a free glucose molecule
5 True/False questions
What is debranching? → Glycogenin is both an enzyme and its substrate consisting of two 37 kD subunits. Each subunit catalyzes addition of a glycosyl unit from UDP glucose to Tyr 194 of other subunit. Subsequently, 7 more glycosyl units are added so that 8 glycosyl units are attached to Tyr 194 for each subunit
What is the overall reaction of UDP glucose formation? → Glucose-1-phosphate +UTP =>UDP-glucose + PPi
What are the properties of Glycogen synthase? → Utilizes a non branched string of at least 11 glycosyl residues long. Branching enzyme transfers a string of typically 7 residues from non reducing end to presumptive branch point.
What is glycogenin? → A very large, branched polymer of glucose residues. Most of the glucose residues are linked by alpha 1,4 glycosidic bonds. branches about every 10th residue are linked by alpha 1,6 glycosidic bonds
How is UDP-glucose formed? → A very large, branched polymer of glucose residues. Most of the glucose residues are linked by alpha 1,4 glycosidic bonds. branches about every 10th residue are linked by alpha 1,6 glycosidic bonds