Noncompetitive Inhibitors

Definition

Noncompetitive inhibitors are molecules that bind to an area other than an enzyme's active site, changing its shape so it can no longer effectively catalyze reactions with its normal substrates.

Analogy

It’s like someone sitting in your lap while you’re trying to drive. They aren’t taking your spot (the active site), but their presence makes it impossible for you to operate (catalyze reactions) properly!

Related terms

Allosteric site: The place on an enzyme where a molecule that is not a substrate may bind, thus changing the shape of the enzyme and influencing its ability to be active.

Feedback inhibition: A method of metabolic control in which the end product of a metabolic pathway acts as an inhibitor of an enzyme within that pathway.

Coenzyme: A non-protein compound necessary for the functioning of an enzyme.