Why is competitive inhibition reversible?

Question

My Biochemistry book mentions that 'competitive inhibition' is a reversible form of inhibition.<Br> But given that the inhibitor is blocking the active site and prevents an enzyme-substrate complex to be formed, how can it be reversible?

Answer 1

This is due to a misconception about molecules in general. In reality, you do not have just one target molecule competing for the active site with a inhibitor. Instead, you have several- from tens to hundreds- of both molecules competing for the active site. Instead of permanently binding to the the active site, an inhibitor attached to the active site, stays for a few fractions of a second, and leaves. At a high concentration, inhibitors continuously interacts with the active site to diminish the number of times the target has access to the active site to near zero.

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