Question

The rate of enzyme reactions rises with the increase in substrate concentration. But it does NOT increase beyond a certain concentration because ______ 

Options

• The enzymes undergo denaturation.

• Free enzyme molecules to bind with the substrate are not available.

• The substrate molecules are available.

• The reaction has to maintain a minimum velocity.

Answer 1

The rate of enzyme reactions rises with the increase in substrate concentration. But it does NOT increase beyond a certain concentration because Free enzyme molecules to bind with the substrate are not available.

Explanation: 

Enzyme molecules bind with the substrate at the active binding site. As we increase the concentration of enzymes more and more substrate molecules will bind thereby increasing the rate of reaction. But it does not increase beyond a certain concentration as all enzyme molecules are bound to substrate and no more are available.