Chapter 4, Problem 9RA

Enzymes increase the rate of chemical reactions by

$\begin{array}{l}\text{a}\text{. increasing the body temperature}\text{.}\hfill \\ \text{b}\text{. decreasing the blood pH}\text{.}\hfill \\ \text{c}\text{. increasing the affinity of reactant molecules for each other}\text{.}\hfill \\ \text{d}\text{. decreasing the activation energy of the reactants}\text{.}\hfill \end{array}$