Comparison between Competitive Inhibitor and Non-Competitive Inhibitor

 

Let me share with you a comparison between Competitive Inhibitor and Non-Competitive Inhibitor.

Aspect Competitive Inhibitor   Non-Competitive Inhibitor
Binding Site on enzyme Binds to the active site of the enzyme. Binds to a site other than the active site (allosteric site).
Competition with substrate Competes with the substrate for the active site. Binds to the enzyme-substrate complex or the enzyme itself without competing with the substrate.
Effect on Enzyme-Substrate Complex Prevents the formation of the enzyme-substrate complex. Alters the shape of the enzyme or active site, making it less effective in catalyzing the reaction.
Reversibility Reversible inhibition Often irreversible inhibition
Enzyme Activity Enzyme activity can be restored by increasing substrate concentration. Enzyme activity cannot be fully restored by increasing substrate concentration.
Graphical Representation In the presence of a competitive inhibitor, the Vmax remains the same, but Km increases. In the presence of a non-competitive inhibitor, both Vmax and Km are altered.
Examples Malonate inhibiting succinate dehydrogenase in the citric acid cycle. Cyanide inhibiting cytochrome c oxidase in the electron transport chain.