• There are?two types?of inhibitors:
  • Competitive?inhibitors have a?similar shape?to that of the?substrate?molecules and therefore?compete?with the substrate for the active site
  • Non-competitive?inhibitors?bind?to the enzyme at an?alternative site, which?alters the shape of the active site?and therefore?prevents?the?substrate?from?binding?to it
• Both types of inhibitors?slow down?or?stop?enzyme activity
• Increasing?the concentration of an inhibitor, therefore,?reduces?the rate of reaction and eventually, if inhibitor concentration continues to be increased, the reaction will?stop completely
• For competitive inhibitors, countering the increase in inhibitor concentration by increasing the substrate concentration?can?increase?the rate of reaction once more (more substrate molecules mean they are more likely to collide with enzymes and form enzyme-substrate complexes)
• For non-competitive inhibitors, increasing the substrate concentration?cannot?increase?the rate of reaction once more, as the shape of the active site of the enzyme remains changed and enzyme-substrate complexes are still unable to form

The effect of inhibitor concentration on the rate of an enzyme-catalysed reaction