Answer: Reaction B has an enzyme.
Step-by-step explanation:
An Enzyme is an biological substance that catalyzes (by speeding up) a biological chemical reaction.
IN NATURE, normal breakdown of material from reactants to products occurs. However, the addition of an enzyme will MODIFY the rate of the SAME reaction, only reducing the time taken in most cases.
Let the first chart be Reaction A, and the second chart be Reaction B.
Thus, the difference between reaction A and B, is simply that reaction B has an enzyme.