Question

The K_m of an enzyme is

• A. one half of the V_max
• B. a dissociation constant
• C. the substrate concentration that gives maximal velocity
• D. the substrate concentration that gives half maximal velocity

Answer 1

Answer: (D)

This value is numerically equal to the substrate concentration at which half of the enzyme molecules are associated with the substrate. K_m value is an index of the affinity of the enzyme for its particular substrate. This is usually expressed as the K_m (Michaelis constant) of the enzyme, an inverse measure of affinity.