ENZYME INHIBITORS

Enzyme inhibitors are molecules that bind to enzymes and interfere with their activity.  They reduce enzyme activity either directly or indirectly.  They affect the function of the active site.  

competitive inhibitors closely resemble the structure of the substrate and competes for the active site but does not remain at the site permanently.  The more substrate present the more likely the substrate is to outcompete the inhibitor and attach to the enzyme.  

Does not resemble the substrate but can bind to the enzyme at a different site and changes hte shape of the active site so that the substrate can no longer attach.  The active sites may regain shape if it leaves.  

Others bind to the enzyme, leaving the enzyme permanently damaged eg.cyanide which is poisonous.  

Enzymes with a second site are called allosteric enzymes.  the inhibitor joins to the allosteric site and acts as a noncompetitive inhibitor.  

With non-competitive inhibitors the substrate and inhibitor are not competing for the same site so increasing the substrate concentration does not effect the inhibitor.