What best describes noncompetitive inhibition?

Noncompetitive inhibition is characterized by the ability of an inhibitor to bind to an enzyme at a site other than the active site. This type of inhibition does not involve competition with the substrate for the active site; instead, the presence of the inhibitor alters the enzyme's function, reducing its activity regardless of whether the substrate is present.

Option B accurately describes this process, as it entails the inhibitor binding to a noncompetitive site on the enzyme. When this binding occurs, it can prevent the enzyme from functioning properly, regardless of the amount of substrate present. This means that the enzyme's ability to convert substrate to product diminishes, but the enzyme itself remains unchanged.

This concept is vital in understanding enzyme kinetics and how various substances can modulate enzyme activity, which is crucial in fields such as pharmacology and biochemistry. The other options do not describe noncompetitive inhibition effectively; they either pertain to other forms of inhibition or activation.