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.

Question

Quizplus · Accepted Answer

The role of an enzyme in an enzyme-catalyzed reaction is to increase the rate at which substrate is converted into product by lowering the activation energy of the reaction. This is achieved by binding the substrate in a specific orientation that favors the formation of the transition state intermediate, thus making the reaction proceed more rapidly than it would without the enzyme.

The Role of an Enzyme in an Enzyme-Catalyzed Reaction Is