Concept #1: Calculating Vmax

Concept #2: Recall: Initial Velocity and Vmax

Example #1: Calculate the maximum reaction velocity (Vmax) of an enzyme if the Km = 7 mM and the initial reaction velocity(V0) = 86.71 μM/sec when the [S] = 25 mM.

Practice: Suppose an enzyme (MW = 5,000 g/mole) has a concentration of 0.05 mg/L. If the *k*_{cat} is 1 x 10^{4} s^{-}^{1}, what is the theoretical maximum reaction velocity for the enzyme?

Practice: For a Michaelis-Menten enzyme, what is the value of V_{max} if at 1/10 Km, the V_{0} = 1 μmol/min.

Practice: Carbonic anhydrase catalyzes the hydration of CO_{2}. The Km of carbonic anhydrase for CO_{2} is 12 mM. The initial velocity (V_{0}) of the enzyme-catalyzed reaction was 4.5 μmole*mL^{-1}*sec^{-1} when [CO_{2}] = 36 mM. Calculate the V_{max} of carbonic anhydrase.

Practice: Triose phosphate isomerase catalyzes the conversion of dihydroxyacetone phosphate (DHAP) to glyceraldehyde-3-phosphate (G3P) during glycolysis; however, this is a reversible reaction. The K_{m} of the enzyme for G3P is 1.8 x 10 ^{-5} M. When [G3P] = 30 μM, the initial rate of the reaction (V_{0}) = 82.5 μmole*mL^{-1}*sec^{-1}. Calculate the V_{max}.