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': 'Oxaloacetate + Acetyl CoA Citrate + CoASHThis reaction is: \nSelect and explain. \nA. Reversible, B. Irreversible, C. Can be reversed by catalase, D. Competitive', 'role': 'user'}, {'content': 'Answer: B \nExplanation: B i.e. IrreversibleFormation of Citric Acid from Acetyl -COA and Oxaloacetate (OAA) is 1st and irreversible step of TCA, giving 7.8 K cal (exergonic reactionQ)', 'role': 'assistant'}]