5 Written questions
5 Matching questions
- What is phosphoglucomutase?
- What is Uridine Diphosphate?
- What does transferase do?
- What converts Glucose 6 phosphate into glucose in liver?
- What role does UDP-glucose play in Glycogen synthesis?
- a Transferase transfers the 3 terminal glucose residues from outer branch to the center, main linear branch
- b Glucose 6 phosphatase converts Glucose 6 phosphate into glucose for export out of the liver and transport to other tissues
- c Glycogen synthesis involves transfer of glucose from UDP-glucose to a growing chain
- d Uridine diphosphate is a nucleotide composed of uracil, ribose and pyrophosphate
- e Phosphoglucomutase is a phospho enzyme and converts Glucose 1 phosphate to glucose 6 phosphate for further metabolism
5 Multiple choice questions
- Glucose-1-phosphate +UTP =>UDP-glucose + PPi
- Alpha 1,6 glucosiase hydrolyzes the alpha 1,6 glucosidic bond to release a free glucose molecule
- 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.
- Must be at least 4 residues away from other branches. Links are alpha 1,6 glycosidic bond
- A glycosyl unit from UDP glucose is transferred to the hydroxyl group at the C4 of the terminal glucose residue forming a alpha 1,4 glycosidic bond. Requires a glycogen molecule that is a minimum of 4 residues to which a glycosyl will be added
5 True/False questions
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
What is debranching? → When glucose residues are removed to the "limit dextran" which is the 4th glucose residue from the branch glucose
What enzyme catalyzes the transfer of glucose from UDP-glucose to a growing chain? → Glucose-1-phosphate +UTP =>UDP-glucose + PPi
How is UDP-glucose formed? → 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 irreversible reaction drives the synthesis of UDP-glucose? → Glucose-1-phosphate +UTP =>UDP-glucose + PPi