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': 'The amino acid producing (a major source of) ammonia in the kidney is \nSelect and explain. \nA. Glutamine, B. Alanine, Aspartate, C. Methionine, D. Glycine', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Formation and secretion ammonia by renal tubular cells maintain acid-base balance. Ammonia is formed from glutamine by glutaminase.', 'role': 'assistant'}]