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': 'Oxaloacetate is formed from \nSelect and explain. \nA. Glutamate, B. Histidine, C. Aspaate, D. Alanine', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Aminotransferase (transaminase) reactions form pyruvate from alanine, oxaloacetate from aspaate, and a-ketoglutarate from glutamate. Because these reactions are reversible, the cycle also serves as a source of carbon skeletons for the synthesis of these amino acids. Other amino acids contribute to gluconeogenesis because their carbon skeletons give rise to citric acid cycle intermediates. Alanine, cysteine, glycine, hydroxyproline, serine, threonine, and tryptophan yield pyruvate; arginine, histidine, glutamine, and proline yield a-ketoglutarate; isoleucine, methionine, and valine yield succinyl-CoA; tyrosine and phenylalanine yield fumarate. Reference: Harper; 30th edition; Page no: 165', 'role': 'assistant'}]