This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory Chain, Subject name: Biochemistry
[{'content': 'In ETC at which complex ATP is not formed - \nSelect and explain. \nA. NADH CoQ reductase, B. Succinate CoQ reductase, C. CoQ-cytochrome-C reductase, D. Cytochrome C oxidase', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Succinate CoQ reductase Complex (I-IV) & Sites (I-III of ATP formation) in ETCComplex I: NADH CoQ-reductasePermit ATP formation (Site I)Act as proton pumpComplex II: Succinate CoQ reductaseNo ATP formComplex III; CoQ - cytochrome - C reductasePermit ATP formation (Site II)Act as proton pumpComplex IV: Cytochrome C oxidasePermit ATP formation (Site III)Act as proton pump", 'role': 'assistant'}]