Final answer:
The relative concentrations of substrates and inhibitors affect enzyme activity by influencing the rate of reaction. Higher substrate concentrations can overcome competitive inhibitor effects, increasing the enzyme's activity, while higher inhibitor concentrations can enhance inhibition.
Step-by-step explanation:
The concentration of substrates and inhibitors plays a significant role in enzyme-catalyzed reactions. In the case of competitive inhibition, where the inhibitor competes with the substrate for the active site, the relative concentrations can impact the extent of inhibition. As substrate concentration increases, it can outcompete the inhibitor, thereby diminishing the effect of inhibition and allowing the enzyme to regain its catalytic activity. Conversely, if the inhibitor concentration is increased, it will more effectively compete with the substrate, leading to increased inhibition of the enzyme.
When considering enzyme concentration, it is often substantially lower than the substrate concentration. Therefore, increasing enzyme concentration will increase the reaction rate linearly, up until the point where the enzymes are saturated with substrates. At this saturation point, additional substrate will not increase the reaction rate.
Overall, the interaction between the concentration of substrate, inhibitor, and enzyme defines the rate of reaction. With higher substrate concentration, until saturation, the rate of reaction increases, whereas an excess of competitive inhibitor can diminish this rate. However, the nature of competitive inhibition allows for the possibility of the substrate to eventually outcompete the inhibitor if its concentration is high enough.