Question

which statement about enzymes is true?
○ enzymes have an active site that has a complementary shape to a substrate.
○ enzymes have an active site that binds to a variety of different substrates.
○ enzymes are not affected by abiotic factors in the environment.
○ enzymes are not affected by biotic factors in the environment.

Explanation:

• For the first option: Enzymes have an active site with a shape complementary to their specific substrate (lock - and - key model or induced - fit model), so this is correct.
• For the second option: Enzymes are specific to their substrates, so the active site does not bind to a variety of different substrates.
• For the third option: Abiotic factors like temperature and pH can affect enzyme activity (e.g., extreme pH or temperature can denature enzymes).
• For the fourth option: Biotic factors like the presence of inhibitors (which can be produced by organisms) can affect enzyme activity.

Answer:

Enzymes have an active site that has a complementary shape to a substrate.