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': 'Succinyl CoA is formed by all except ? \nSelect and explain. \nA. Proline, B. Isoleucine, C. Methionine, D. Valine', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Histidine, proline, glutamine, arginineGlutamatea a-ketoglutaratelsoleucine, methionine, valineSuccinyl CoATyrosine, phenylalanineFumarateTryptophanAlanine a PyruvateHydroxyproline, serine, cysteine, threonine, glycinePyruvate', 'role': 'assistant'}]