This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of carbohydrate, Subject name: Biochemistry
[{'content': 'Enzymes not used in glycogen metabolism \nSelect and explain. \nA. Glycogen phosphorylase B, B. Glycogen synthase I, C. Glycogen synthase C, D. Glycogen synthase D', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The liver phosphorylase-b is the inactive form. It becomes active on phosphorylation. The active form is phosphorylase-a.Glycogen synthase exists in two distinct forms that can be interconveed by the action of specific enzymes; active dephosphorylated glycogen synthase(glucose-6-p-independent) and less active, phosphorylated glycogen synthase D(glucose-6-p-dependent.Ref: DM Vasudevan, page no: 127', 'role': 'assistant'}]