Why are enzymes necessary?
a. to slow the rate of decomposition
b. to act as a catalyst in chemical reactions
c. to conserve the stored energy of a cell

The correct answer is -

B. to act as a catalyst in chemical reactions.

Enzymes can be described as large biomolecules, which are primarily proteins and drive many chemical reactions, necessary for sustaining life. They are also knwon as biological catalyst.

Enzymes increase the rate of the chemical reaction by decreasing the activation energy of the reaction.

Therefore, they act as catalyst in chemical reactions.

a physical change is being made.