This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
[{'content': 'Which favours gluconeogenesis in the fasting state \nSelect and explain. \nA. Citrate activation of acetyl CoA carboxylase, B. Acetyl CoA activation of pyruvate carboxylase, C. Fructose 1, 6 bisphosphate stimulation of pyruvate kinase, D. Fructose 2, 6 bisphosphate stimulation of phosphofructokinase- 1', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Acetyl CoA activation of pyruvate carboxylase\n\nIn starvation, glucagon secretion is increased.\nGlucagon increases fatty acid mobilization and their oxidation to yield acetyl CoA, NADH and ATP. These compound inhibit the PDH complex and acetyl CoA stimulates pyruvate carboxylase. Thus, the available pyruvate is not converted to acetyl CoA but to oxaloacetate for gluconeogenesis.\n\nAbout other options\n\nAcetyl CoA carboxylase is the most important regulating enzyme in fatty acid synthesis. It is activated by citrate, which increases in concentration in the well-fed state (not during starvation).\nPyruvate kinase and phosphofructokinase-I are regulating enzymes in glycolysis. Their activity is inhibited during starvation.', 'role': 'assistant'}]