Question

Which statement describes the currently accepted theory of how an enzyme and its substrate fit together?

• A. As the product is released, the enzyme breaks down
• B. The enzyme is like a key that fits into the substrate, which is like a lock
• C. The active site is permanently changed by its interaction with the substrate
• D. As the substrate binds to the enzyme, the shape of the enzyme site changes to accommodate the reaction

Answer 1

The correct option is D As the substrate binds to the enzyme, the shape of the enzyme site changes to accommodate the reaction

According to the currently accepted theory, the active site has a flexibility of shape, thus when an appropriate substrate comes in contact with the active site of enzyme, the shape of the active site would change to fit with the substrate. This theory is known as "Induced Fit Hypothesis".
So, the correct answer is 'As the substrate binds to the enzyme, the shape of the active site changes to accommodate the reaction'.