Question

The role of an enzyme in an enzyme-catalyzed reaction is to:
A) bind a transition state intermediate, such that it cannot be converted back to substrate.
B) ensure that all of the substrate is converted to product.
C) ensure that the product is more stable than the substrate.
D) increase the rate at which substrate is converted into product.
E) make the free-energy change for the reaction more favorable.

Answer 1

The correct option is (D).

Explanation:

• In enzyme-catalyzed reaction enzyme acts as a catalyst and these occur in organic solvents.  
• Catalysts help in reducing the activation energy for reactions.
• The rate or speed of the formation of a product is inversely proportional to its activation energy.
• Thus, as the activation energy is lowered by the catalyst, the rate of reaction is increased.
• Thus, the increase in rate at which the substrate is converted into product is done by enzyme.