Explain the role of enzymes as biological catalysts that lower the activation energy of a reaction.

Enzymes are one kind of protein which functioning as catalyst  that speed up reactions by lowering activation energy.Enzyme accelerate a reaction without altering its chemical equilibrium.

Explanation:

Energy which is required for  start a biochemical reaction is called activation energy.Activation Energy helps to jump and start a thermodynamically favorable reactions.

Enzymes can  many  way to its activation energy.

1. The enzyme may hold the substrates in such a way as to distort the substrate bonds closer to their form in the transition state. This reduces the amount of energy needed to complete the transition.

2.Enzyme create a charge distributor which opposite of transition state his lowers the energy of the transition state and decreases the activation energy.

3.The enzyme may reduce the reaction entropy   by bringing substrates together in the correct orientation to react.

4. The enzyme may provide a completely different chemical pathway for the reaction. It may form new bonds in the ES complex that would be difficult to form without the enzyme.

the answer to your question is:

c. complementary base-pairing