This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of protein and amino acid, Subject name: Biochemistry
[{'content': "In Kreb's cycle and Urea cycle the linking component is \nSelect and explain. \nA. Arginine, B. Aspaate, C. Ammonia, D. Fumarate", 'role': 'user'}, {'content': 'Answer: D \nExplanation: Urea cycle * Cleavage of argininosuccinate by argininosuccinate lyase, results in formation of arginine and release of the aspaate skeleton as fumarate (funnelled into TCA cycle) * Subsequent addition of water to fumarate forms l-malate, with subsequent oxidation forms oxaloacetate, followed by its transamination by glutamate aminotransferase then re-forms aspaate. * Argininosuccinate synthase links aspaate and citrulline forms argininosuccinate. * Thus the urea cycle is linked to TCA cycle through fumarate Ref:- Harper 30/e; pg num:- 294', 'role': 'assistant'}]