This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Enzymes, Subject name: Biochemistry
Aspirin irreversibly inhibits the following enzyme in the formation of eicosanoids: 
Select and explain. 
A. Lipoxygenase, B. Cyclooxygenase, C. Phospholipase-A2, D. Peroxidase
B: Cyclooxygenase
Answer: B: Cyclooxygenase 
Explanation: Ans. B. CyclooxygenaseCyclooxygenase is required for the synthesis of prostaglandins by arachidonic acid. Aspirin, indomethacin, brufen, phenyl butazone and other NSAIDS inhibits COX (Cyclooxygenase). Aspirin inhibits COX of both PGHS-1 and PGHS-2 by acetylation