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
[{'content': "Suicidal enzyme is: \nSelect and explain. \nA. Lipoxygenase, B. Cycloxygenase, C. Thromboxane synthase, D. 5'Nucleotidase", 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. B. CycloxygenaseCyclooxygenase is a "Suicide Enzyme" "Switching off" of prostaglandin activity is partly achieved by are markable property of cyclooxygenase -- that of self-catalyzed destruction; i.e., it is a "suicide enzyme." Quickreview-CyclooxygenaseCyclooxygenase (COX) (also called prostaglandin H synthase)Involved in Prostanoid (Prostaglandin Thromboxane and Prostacyclin) synthesisThis enzyme has two activities, acyclo oxygenase and peroxidase.COX is present as two isoenzymes, COX-1 and COX-2.Drugs acting as inhibitors COXNSAID-Aspirin-inhibits COX-1 and COX-2.-Indomethacin and ibuprofen-inhibit cyclooxygenases by competing with arachidonate.-Coxibs--selectively inhibit COX-2-Some coxibs have been withdrawn or suspended from the market due to undesirable side effects and safety issues.Anti-inflammatory Corticosteroids-Transcription of COX-2-- but not of COX-1-- is completely inhibited by corticosteroids.', 'role': 'assistant'}]