Which of the following statements about the active site of an enzyme is correct?

• A. The active site has a fixed structure (shape).
• B. Coenzymes are rarely found in the active site of an enzyme.
• C. The structure of the active site is not affected by changes in temperature.
• D. The active site allows the reaction to occur under the same environmental conditions as the reaction without the enzyme.
• E. The active site may resemble a groove or pocket in the surface of a protein into which the substrate fits.

Answer: (E)

Verified step by step guidance

1. Understand that enzymes are biological catalysts that speed up chemical reactions by lowering the activation energy required for the reaction to occur.
2. Recognize that the active site of an enzyme is the region where substrate molecules bind and undergo a chemical reaction.
3. The active site is typically a groove or pocket on the enzyme's surface, which is specifically shaped to fit the substrate, much like a key fits into a lock.
4. The shape and chemical environment of the active site are critical for the enzyme's specificity and catalytic activity, and they can be influenced by factors such as temperature and pH.
5. Coenzymes, which are non-protein molecules, often assist in the catalytic activity of enzymes by binding to the active site and participating in the reaction.