Competitive enzyme inhibition occurs where a molecule that prevents enzyme function binds to the orthosteric site of a target enzyme. As the inhibiting molecule is present in the same environment as the endogenous agonist, and binds to the same site, it is known as a competitive inhibitor.
When the inhibitor binds to the enzyme’s orthosteric site, the catalytic process of the enzyme is unable to occur. This prevents the enzyme-substrate complex from forming, reducing the enzyme activity.
The residence time of the inhibitor in the active site determines the inhibitory rate, as well as the substrate concentration. Where [substrate] is sufficiently higher than [inhibitor], the inhibitory effect will be minimal and v_max will be reached.