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': 'The activities of all the following enzymes are increased in starvation except \nSelect and explain. \nA. Pyruvate kinase, B. Pyruvate carboxylase, C. Phosphoenolpyruvate carboxykinase, D. Glucose 6-phosphatese', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Step 9 of Glycolysis i. Phosphoenolpyruvate (PEP) is dephosphorylated to pyruvate, by pyruvate kinase. First PEP is made into a transient intermediary of enol pyruvate; which is spontaneously isomerized into keto pyruvate, the stable form of pyruvate. ii. One mole of ATP is generated during this reaction. This is again an example of substrate-level phosphorylation (Fig. 9.13). iii. The pyruvate kinase is a key glycolytic enzyme. This step is irreversible. reversal, however, can be brought about in the body with the help of two enzymes (pyruvate kinase and phosphoenolpyruvate carboxykinase) and hydrolysis of 2 ATP molecules. starvation activation of pyruvate kinase brought to glycolysis.Ref: DM Vasudevan, 7th edition, page no: 109', 'role': 'assistant'}]