In the fed state, glucose entering hepatocytes is phosphorylated to glucose-6-phosphate and then converted to glucose-1-phosphate, which enters glycogen synthesis. The enzyme that converts glucose-1-phosphate to UDP-glucose for glycogen synthesis is:

• A Glycogen phosphorylase
• B Glycogen synthase
• C UDP-glucose pyrophosphorylase (UDP-glucose:pyrophosphate glycosyltransferase) ✓
• D Phosphoglucomutase

Explanation

UDP-glucose pyrophosphorylase catalyzes the reaction between glucose-1-phosphate and UTP to form UDP-glucose and pyrophosphate. The subsequent hydrolysis of pyrophosphate by pyrophosphatase drives this reaction forward thermodynamically. UDP-glucose is the activated sugar donor used by glycogen synthase to add glucosyl residues to the growing glycogen chain via alpha-1,4-glycosidic bonds.

Reference: Harper's Illustrated Biochemistry, 32nd ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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