The velocity of an enzyme-catalyzed reaction that follows Michaelis-Menten kinetics was
measured at several substrate concentrations (shown below).
i. Calculate 𝐾M and V𝑚𝑎𝑥 from the data given.
ii. Determine KM and Vmax
iii. The second set of velocities represent the rate of the reaction when an inhibitor is
added. Plot these on the same graph as the first and determine KM and Vmax
iv. What type of inhibitor is it?
[S](M) V0 (μM/min) V(+ inhibitor)
0.00006 6.66 4
0.0001. 9.30 3
0.002. 15 6
0.006 22.03 8
0.08 29 9
0.2. 35.6 10.6
Vmax is the maximal rate of the reaction. [Substrate] is the concentration of the substrate. Km is the Michaelis-Menten constant which shows the concentration of the substrate when the reaction velocity is equal to one half of the maximal velocity for the reaction.