What are competitive and non-competitve inhibitors?

Inhibitors INHIBIT the ACTIVITY OF ENZYMES. This means fewer enzymes are able to break up substrate, and so whatever reaction is taking place, slows down. Inhibitors can be found for example, in poison or insecticides, and may be used in drugs.

COMPETITIVE INHIBITORS:

1 - These have a similar structure to the substrate, so will bind to the ACTIVE SITE of the enzyme.

2 - The best way to remember them, is to know that they COMPETE with the substrate.

3 - This then means fewer ENZYME-SUBSTRATE COMPLEXES form, and the reaction slows.

NON-COMPETITIVE INHIBITORS

1- These are called 'non-competitive' simply because they DO NOT COMPETE with the substrate for the active site of the enzyme.

2- Instead, they bind to another part of the enzyme called a BINDING SITE. When they do this, this changed the structure of the enzyme, resulting in the shape of the ACTIVE SITE changing.

3- The active site is no longer a complementary shape to the substrate, so fewer ENZYME-SUBSTRATE COMPLEXES can form.