Final answer:
When enzymes are saturated, the reaction follows zero-order kinetics, meaning the reaction rate is constant and does not depend on substrate concentration.
Step-by-step explanation:
When enzymes are saturated with substrate, the rate of reaction does not increase with an increase in substrate concentration because all active sites of the enzyme molecules are occupied, hence the reaction rate is at its maximum. Under these conditions, the reaction follows zero-order kinetics. This means that the reaction rate is constant and independent of the concentration of the substrate, leading to a linear change in the concentration of the reactant with time. The zeroth-order kinetics are characterized by a constant rate that is independent of the concentration of the reactant, as opposed to first-order kinetics where the rate is directly proportional to the concentration of one reactant, or second-order kinetics where the rate is proportional to the square of the concentration of one reactant.