Final answer:
Km is the substrate concentration at which the velocity of the enzyme catalyzed reaction is half the maximum velocity. It is a key kinetic factor in enzymatic reactions.
Step-by-step explanation:
Km is defined as the substrate concentration at which the velocity of the enzyme catalyzed reaction is half the maximum velocity. It is a key kinetic factor in enzymatic reactions. When the velocity is half the maximum velocity, V = ½Vmax. The value of Km can be determined experimentally by measuring the reaction rate at different substrate concentrations and plotting it on a Michaelis-Menten plot.