Which term describes substances that reduce the activity of an enzyme by mimicking the substrate?

The term that describes substances that reduce the activity of an enzyme by mimicking the substrate is competitive inhibitors. These inhibitors bind to the active site of the enzyme, which is the same site where the substrate would normally bind. Because they resemble the substrate structurally, they compete with the substrate for access to the active site. This competition can decrease the rate of the reaction, as the enzyme becomes less available for the real substrate.

Understanding competitive inhibition is important because it highlights how enzyme activity can be regulated through structural mimicry, affecting metabolic pathways. In contrast to other types of inhibitors, such as noncompetitive inhibitors, which bind to sites other than the active site and reduce overall enzyme activity regardless of substrate presence, competitive inhibitors specifically compete with the substrate. This competitive nature allows for potential reversal of inhibition by increasing the concentration of the substrate, effectively outcompeting the inhibitor.