All chemical reactions require activation energy to break chemical bonds and begin the reaction. The need for activation energy acts as a barrier to the chemical reaction occurring and/or to the speed at which it occurs. Consider the graph above. Each represents the activation energy required without an enzyme. How will this graph change if an enzyme is added to the system?

A ΔG will be higher.ΔG will be higher.
B Ea will be lower.E a will be lower.
C ΔG and Ea will be lower.ΔG and E a will be lower.
D Ea and the energy of products will both be lower.

B. Ea will be lower.