SAT Biology Practice Test 5: Enzymes and Reactions

1. As a reaction proceeds, reactants form a transition state, which then forms the products. An enzyme affects the energy of the

A. products only
B. reactants only
C. transition state only
D. products and reactants
E. transition state and products

2. Which term most nearly means substrate?

A. Reactant
B. Product
C. Activation energy
D. Active site
E. Inhibitor

3. Which of these describes a characteristic of the induced-fit model but not the lock-and-key model?

A. The substrate binds to the active site.
B. The enzyme lowers the activation energy of the reaction.
C. The enzyme is changed by the substrate.
D. The substrate is chemically changed by the enzyme.
E. The enzyme is altered by the reaction.

4. Which of these is likely to reduce enzyme activity?

I. Increasing pH level

II. Decreasing temperature

III. Placing enzyme in a nonpolar liquid

A. I only
B. II only
C. III only
D. I and II
E. I, II, and III