Question

There is a mutation in the rate limiting enzyme which prevents it from binding its substrate. How will this mutation affect the cholesterol biosynthetic pathway, when cholesterol levels are high in the organism?

Answer 1

In the cholesterol biosynthetic pathway, the rate-limiting step is the reduction of HMG-CoA, which takes place in the existence of the HMG-CoA reductase enzyme. In case, when mutation takes place within the mentioned enzyme, it loses the tendency to combine with the substrate HMG-CoA, and as a consequence, the pathway fails to move forward and synthesis of cholesterol stops.

When the levels of cholesterol are high within the organism than the mutation of the enzyme HMG-CoA reductase results in less synthesis of cholesterol within the body of the organism and will eventually assist in balancing the level of cholesterol present within the body.