Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Statins produced by the yeast Monascus purpureus are used as blood-cholesterol lowering agents.
Reason (R): Statins act by competitively inhibiting the enzyme responsible for synthesis of cholesterol.
In the light of the above statements, choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Both (A) and (R) are true and (R) is the correct explanation of (A).
Assertion (A): Statins produced by the yeast Monascus purpureus are used as blood-cholesterol lowering agents. — True. A is about the use of statins. Statins are produced by the yeast Monascus purpureus and have been commercialised as blood-cholesterol lowering agents.
Reason (R): Statins act by competitively inhibiting the enzyme responsible for synthesis of cholesterol. — True. R is about how statins act. They competitively inhibit the enzyme responsible for the synthesis of cholesterol; that is, the statin competes with the normal substrate for the enzyme, so the enzyme works less.
Why R explains A? When the enzyme that makes cholesterol is blocked, the body makes less cholesterol, and the cholesterol level in the blood falls. So the mechanism in R is the reason why statins can be used as cholesterol lowering agents. R is the correct explanation of A.
NCERT Extract:
Chemicals, Enzymes and other Bioactive Molecules – “… Another bioactive molecule, cyclosporin A, that is used as an immunosuppressive agent in organ-transplant patients, is produced by the fungus Trichoderma polysporum. Statins produced by the yeast Monascus purpureus have been commercialised as blood-cholesterol lowering agents. It acts by competitively inhibiting the enzyme responsible for synthesis of cholesterol.”