This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Proteins and Amino Acids, Subject name: Biochemistry
[{'content': 'Ammonia is toxic to the brain because it leads to depletion of which substrate? \nSelect and explain. \nA. Succinate, B. Alpha ketoglutarate, C. Isocitrate, D. Fumarate', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. B. Alpha ketoglutarateAmmonia reacts with Glutamate to form Glutamine. The Glutamate is formed from alpha keto glutarate an intermediate of TCA Cycle. So alpha ketoglutarate is depleted.', 'role': 'assistant'}]