Question

multiple choice question

which best defines an active site?

region of an enzyme where a noncompetitive inhibitor binds
region on the substrate where the enzyme binds
region of an enzyme where the substrate binds

Explanation:

Analyze the definition of an active site

An active site is the specific region of an enzyme where substrate molecules bind and undergo a chemical reaction.

Evaluate the given options

• "Region of an enzyme where a noncompetitive inhibitor binds": Incorrect. Noncompetitive inhibitors bind to an allosteric site, not the active site.
• "Region on the substrate where the enzyme binds": Incorrect. The active site is located on the enzyme, not on the substrate.
• "Region of an enzyme where the substrate binds": Correct. This matches the standard biological definition of an active site.

Answer:

• Region of an enzyme where a noncompetitive inhibitor binds
• Region on the substrate where the enzyme binds
• Region of an enzyme where the substrate binds (Correct answer)