Question

Enzyme hexokinase is inhibited by excess glucose 6-P. It is

• A. Competitive inhibition
• B. Feed-back allosteric inhibition
• C. Non-competitive inhibition
• D. Positive feed-back

Answer 1

Answer: (B)

Feed-back allosteric inhibition

Feedback inhibition is the process by where the end product terminates the reaction. The accumulation of the end product interferes with the enzymatic activity by changing the shape of its active site. On changing the shape of the active site, the substrate does not attach to the active site and thus the reaction terminates. During glycolysis, the glucose changes to glucose 6 phosphates in the presence of hexokinase. When the amount of glucose 6 phosphate exceeds it deactivate hexokinase.

So, the correct answer is option B.