For questions 4 and 5, refer to the passage below.
Many cells make and use an enzyme, called catalase,
to facilitate the decomposition of hydrogen peroxide
(H2O2). The products of the decomposition are
hydrogen (H2) and oxygen (O2).
4. What is the effect of catalase on the decomposition
of hydrogen peroxide?
A. It decreases the activation energy needed to
start the reaction.
B. It decreases the total energy released by
the reaction.
C. It increases the total energy absorbed by
the reaction.
D. It changes the ratio of the amounts of the
two products.
