Which of these statements about enzyme inhibitors is true?

• A. A competitive inhibitor binds to the enzyme at a place that is separate from the active site.
• B. A noncompetitive inhibitor does not change the shape of the active site.
• C. When the product of an enzyme or an enzyme sequence acts as its inhibitor, this is known as positive feedback.
• D. Inhibition of enzyme function by compounds that are not substrates is something that only occurs under controlled conditions in the laboratory.
• E. The action of competitive inhibitors may be reversible or irreversible.

Answer: (E)

Verified step by step guidance

1. Understand the role of enzyme inhibitors: Enzyme inhibitors are molecules that bind to enzymes and decrease their activity. They can be classified into different types based on their mechanism of action.
2. Identify the types of enzyme inhibitors: The two main types are competitive and noncompetitive inhibitors. Competitive inhibitors bind to the active site of the enzyme, while noncompetitive inhibitors bind to a different site, causing a change in enzyme shape.
3. Evaluate the statements: Analyze each statement to determine its accuracy based on the definitions and characteristics of competitive and noncompetitive inhibitors.
4. Clarify the concept of feedback inhibition: Feedback inhibition occurs when the product of a reaction inhibits the enzyme that produces it, typically as a form of negative feedback to regulate metabolic pathways.
5. Determine the correct statement: The statement 'The action of competitive inhibitors may be reversible or irreversible' is true, as competitive inhibitors can either temporarily or permanently bind to the active site, affecting enzyme activity.