How does a competitive inhibitors work?

Competitive inhibitors work by binding to the active site of an enzyme, competing with the substrate for that site. This binding prevents the substrate from attaching, thereby reducing the rate of the enzyme-catalyzed reaction. The effect of a competitive inhibitor can be overcome by increasing the concentration of the substrate, which can outcompete the inhibitor for binding to the enzyme. As a result, the maximum reaction velocity (Vmax) remains the same, but the apparent affinity of the enzyme for the substrate (reflected in the Km value) is decreased.