Question

maltase is an enzyme found in the small intestine. it helps break down maltose during the process of digestion.
which of the following best describes what happens when maltose binds with maltase?
choose 1 answer:
a the conformation of maltose is already complementary to the active site of maltase, so maltose binds to the active site without either structure changing conformation.
b maltose binds to an allosteric site on maltase, causing the conformation of the allosteric site to change slightly.
c the conformation of maltose changes, and then maltose binds to the active site of maltase.
d maltose binds to the active site of maltase, causing the conformation of the active site to change slightly.

Explanation:

Enzymes like maltase follow the induced fit model: when a substrate (maltose) binds to the enzyme's active site, the active site slightly changes its conformation to better fit the substrate, optimizing the catalytic reaction. Option A is incorrect because it describes the outdated lock-and-key model, which does not account for conformational changes. Option B is wrong because maltose binds to the active site, not an allosteric site. Option C is incorrect because it is the enzyme's active site that changes, not the substrate's conformation first.

Answer:

D. Maltose binds to the active site of maltase, causing the conformation of the active site to change slightly.