Chemicals which decrease the rate of enzyme catalyzed reactions are called inhibitors.
There are 3 types of inhibitors
1.Competitive inhibition
2.Non-competitive inhibition
3.End product inhibition
1. COMPETITIVE INHIBITION
competitive inhibitors are some what similar to the specific substrate of the enzyme and they can fit into the active site of enzyme.
Therefore competition occurs between the specific substrate molecule and inhibitor molecule to occupy active sites.
When inhibitors join enzyme molecules active sites are blocked temporary hence substrate molecules unable to combine with enzymes as enzyme substrate complex formation is affected the rate of the reaction decreases.
2.NON-COMPETITIVE INHIBITION
Non-competitive inhibitors do not combine with active sites of enzymes instead they fit into ALLOSTERIC SITES of the enzyme then they change the shape of active site. Therefore substrate unable to combine with enzyme further .
3.END PRODUCT INHIBITION
When the end product of a series of reaction causes and inhibition over one or more enzyme of the path.
It referred as end product inhibition.