Which of the following statements about enzymes are true? Choose all that apply:
a. an enzyme yields a specific product, whereas a nonbiologival catalyst may produce more than one product, and side reactions may occur.
b. generally, an enzyme is specific for a substrate. for example, thrombin catalyzes the hydrolysis of the peptide bond between Arg and Gly.
c. a substrate must bind to the active site before a reaction occurs.
d. reactions occur at the active site, which usually consists of a crevice on the surface of the enzyme
e. nonbiological catalysts and enzymes tend to have a similar degree of reaction specificity."