SAT Subject Biology Practice Question 22: Answer and Explanation
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.
Correct Answer: C
The induced-fit model states that the shape of the enzyme is altered by binding with the substrate. This is not a feature of the lock-and-key model. Neither model posits that the enzyme is changed by the reaction.