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
In TCA cycle, NADH is produce at all sites except - 
Select and explain. 
A. Isocitrate dehydrogenase, B. Succinate dehydrogenase, C. Malate dehydrogenase, D. a Ketoglutarate dehydrogenase
B: Succinate dehydrogenase
Answer: B: Succinate dehydrogenase 
Explanation: Ans. is 'b' i.e., Succinate dehydrogenase NADH is produced and CO , is liberated at 3 steps :Conversion of isocitrate to a-ketoglutarate by isocitrate dehydrogenaseConversion of a-ketoglutarate to succinyl CoA by a-ketoglutarate dehydrogenaseConversion of L-malate to oxaloacetate by malate dehydrogenase.