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': 'Which of the following when absent would impair the rate-limiting step of glycogenolysis? \nSelect and explain. \nA. 1,4-Glucoronosyl troanterase, B. Glycogen synthetase, C. Glycogen phosphorylase, D. Phosphoglucomutase', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The key enzyme for glycogenolysis is glycogen phosphorylase.Glycogen phosphorylase removes glucose as glucose-1- phosphate from glycogen.Alpha-1,4- glycosidic linkage in glycogen are cleaved.Ref: DM Vasudevan, 7th edition, page no: 124', 'role': 'assistant'}]