Biology · Enzymes
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Which of the following statement is incorrect with reference to the enzyme action?
- A
Substrate binds with the enzyme at its active site
- B
Non-competitive inhibitor binds the enzyme at a site distinct from that of active site
- C
Addition of a lot of succinate do not reverse the inhibition of succinic dehydrogenase by malonate
- D
Malonate is a competitive inhibitor of succinic dehydrogenase
The correct answer is Option C, which states that 'Addition of a lot of succinate do not reverse the inhibition of succinic dehydrogenase by malonate.' This is incorrect because malonate is a competitive inhibitor, and increasing the concentration of succinate can indeed reverse the inhibition by outcompeting malonate for the active site on the enzyme.
Option A is correct as it describes the normal substrate-enzyme interaction. Option B is also correct since non-competitive inhibitors bind elsewhere on the enzyme. Option D is correct because malonate is a known competitive inhibitor of succinic dehydrogenase, and thus the statement accurately describes its mechanism of action.
This statement is correct as substrates interact with enzymes at their active sites to form the enzyme-substrate complex.
This statement is correct. Non-competitive inhibitors bind to an enzyme at a location other than the active site, affecting the enzyme's function regardless of substrate concentration.
This statement is incorrect. Malonate is a competitive inhibitor of succinic dehydrogenase, meaning that increasing succinate concentration can outcompete malonate and restore enzyme activity.
This statement is correct. Malonate competes with succinate for the active site of succinic dehydrogenase, inhibiting its activity when present.
Tagged under Biology · Enzymes · 2025