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, CO2 is released from: 
Select and explain. 
A. Thiokinase, B. Isocitrate dehydrogenase, C. Citrate dehydrogenase, D. Alpha ketoglutrate
B: Isocitrate dehydrogenase
Answer: B: Isocitrate dehydrogenase 
Explanation: B i.e. Isocitrate dehydrogenase 2 molecules of carbon dioxide are released in TCA cycle. One before and one after a - ketoglatarate. Enzymes used are - isocitrate dehydrogenase and a ketoglutarate dehydrogenaseQ respectively.