What occurs in the case of non-competitive inhibition?

In non-competitive inhibition, the inhibitor binds to an enzyme at a site distinct from the active site. This binding can occur whether the substrate is bound to the enzyme or not, which means that it does not prevent substrate binding but instead alters the enzyme's conformation and decreases its catalytic activity. As a result, the maximum reaction rate (Vmax) is lowered since the inhibitor reduces the overall amount of active enzyme available for catalysis. However, the affinity of the enzyme for the substrate (represented by the Michaelis constant, Km) remains unchanged because the substrate can still bind to the enzyme, albeit less effectively in terms of producing product. This characteristic defines non-competitive inhibition and distinguishes it from other types of inhibition mechanisms.