Final answer:
HMG CoA reductase is the enzyme inhibited by statin drugs to reduce cholesterol biosynthesis in the body. These drugs block a vital step in the pathway, demonstrating the enzyme's central role in cholesterol regulation.
Step-by-step explanation:
The enzyme in cholesterol biosynthesis subject to statin drug inhibition is HMG CoA reductase. Statins are a class of drugs that significantly reduce cholesterol levels by inhibiting the synthesis of cholesterol from lipids within the body. Regulation of cholesterol biosynthesis primarily occurs at the HMG-CoA reductase step, which is an essential enzyme that catalyzes the conversion of HMG-CoA to mevalonate, a crucial early step in the production of cholesterol.
Statins work as inhibitors of HMG-CoA reductase, thereby lowering the amount of cholesterol synthesized by the body. This is the very mechanism by which these drugs help to regulate cholesterol levels and contribute to the prevention of cardiovascular diseases. The action of these drugs underscores the importance of HMG-CoA reductase in the cholesterol biosynthesis pathway.