Final answer:
Doubling the concentration of enzyme will double Vmax due to more active sites being available, but it will not alter KM as it is an inherent characteristic of enzyme-substrate affinity.
Step-by-step explanation:
When considering the effect of doubling the concentration of enzyme on the kinetic parameters Vmax and KM, we refer to the principles of Michaelis-Menten kinetics. Doubling the enzyme concentration will double the Vmax because Vmax is directly proportional to the amount of enzyme available. This means that the maximum rate of the reaction (Vmax) will increase since there are more active sites available for substrate binding. However, doubling the enzyme concentration does not alter the KM. The Michaelis constant (KM) represents the affinity of the enzyme for its substrate and is a fixed characteristic for each enzyme-substrate pair, independent of enzyme concentration. Therefore, the correct answer is that doubling the concentration of enzyme will double the Vmax and not alter the KM, which corresponds to option 1).