This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Carbohydrates, Subject name: Biochemistry
NAD+ reduced by all of the following enzymes except: 
Select and explain. 
A. Alpha ketoglutarate dehydrogenase, B. Iso-citrate dehydrogenase, C. Malate dehydrogenase, D. Succinyl dehydrogenase
D: Succinyl dehydrogenase
Answer: D: Succinyl dehydrogenase 
Explanation: Ans. D. Succinyl dehydrogenaseNiacin acts as electron acceptor for the following enzymes:Isocitrate dehydrogenaseAlpha ketoglutarateMalate dehydrogenase