Final answer:
Doubling the concentration of an enzyme does not change its Michaelis constant (Km), as Km is an intrinsic characteristic of the enzyme-substrate interaction that is independent of enzyme concentration. While the overall reaction rate may increase due to more enzyme molecules being available, the Km value remains the same.
Step-by-step explanation:
The question of what happens to the Michaelis constant (Km) when the concentration of the enzyme is doubled pertains to the field of enzyme kinetics. Km is a measure of the affinity of an enzyme for its substrate, and it is defined as the substrate concentration at which the velocity of the enzyme-catalyzed reaction is half the maximum velocity.
Doubling the enzyme concentration does not change the Km, because Km is an inherent property of the enzyme-substrate interaction, not of enzyme concentration.
The relationship is described by the Michaelis-Menten equation, which under steady-state conditions is represented as KM = (k₂ + ka)/k₁, where 'k₁' is the rate constant for enzyme and substrate coming together, 'k₂' is the rate constant for product formation, and 'ka' might represent another dissociation constant in complex reaction schemes. Since increasing enzyme concentration does not alter these constants, Km remains unchanged.
However, it should be noted that although Km remains constant, the overall reaction rate may increase with higher enzyme concentrations, since there are more enzyme molecules available to perform the reaction. Still, this change in the rate is independent of the Km value.