Which enzy me is irreversibly inhibited by aspirin?

Ans. is 'b' i.e., Cyclooxygenase o Aspirin, indomethacin and diclofenac are NSAIDs.o All NSAIDs inhibit cvcloxvgenase.NON STEROlPOL ANTIINFL.AMM ATORY PRI GS (NSAIDS)o Also called "nonnarcotic, nonopioid or aspirin tike analgesicso Important drugs are1. Nonselective Cox inhibitors (traditional NSAIDs)o Aspirino Diclofenaco Indomethacino Ketorolaco Ibuprofeno Piroxicamo Phenylbutazono Naproxen2 Preferential COX-2 inhibitors (COX 2 > COX 1)o Nimesulideo Meloxicamo Nabumetone3 Selective COX-2 inhibitorso Celecoxibo Parecoxibo Rofecoxibo Etoricoxibo Lumiracoxibo Valdecoxib4 nAnalgesic-antipyretics without antiinflammatory actiono Paracetamolo Metamizolo NefopamMechanism of actiono All NSAIDs inhibit cyclooxygenase inhibit synthesis of prosaglandins.o Aspirin inhibits COX irreversibly by acetylating one of its serine residues, return of COX activity depends on synthesis of fresh enzyme.o Other NSAIDs are competitive and reversible inhibitors of COX, return of activity depends on their dissociation from the enzyme which in turn is governed by the pharmacokinetic characteristics of the compound.