Essential Biochemistry - Enzymes (Section 4 - No. 29)
The Michaelis constant (Km) is:
Not changed by the presence of non-competitive inhibitor
Equaled to 1/2 Vmax
The substrate concentration at 1/2 Vmax
The equilibrium constant for the dissociation of ES complex
Explanation
Km is the substrate concentration at which the reaction rate is half of Vmax.