Competitive and Non-Competitive Inhibition

COMPETITIVE INHIBITION

• Competitive inhibitors have a similar structure to a substrate, and so compete with that substrate to occupy the active site. 
• They will remain temporarily bound to the active site of an enzyme, preventing the substrate molecule from joining with the active site and forming an enzyme-substrate complex.
• HOWEVER, increasing the substrate concentration decreases the effect of the inhibitor. As the substrate concentration increases, the likelihood of the substrates and available active sites colliding and forming enzyme-substrate complexes increases, leaving fewer active sites available for the competitive inhibitor to occupy. 

In the graph above, the same rate of reaction is reached, just with a greater substrate concentration. This is because, with competitive inhibitors present…