Final answer:
Competitive inhibition increases the value of the Michaelis constant (Km) by reducing the affinity of the enzyme for its substrate.
Step-by-step explanation:
Competitive inhibition occurs when a molecule similar to the substrate binds reversibly to the enzyme's active site, competing with the substrate for binding. This inhibitor does not undergo the same chemical reaction as the substrate. The effect of competitive inhibition on the Michaelis constant (Km) is to increase its value. This means that competitive inhibitors reduce the affinity of the enzyme for its substrate, making it harder for the substrate to bind to the enzyme.