Question

Initial rate data for an enzyme that obeys Michaelis-Menten kinetics are shown in the following table. When the enzyme concentration is 3 nmol ml−1, a Lineweaver-Burk plot of this data gives a line with a y-intercept of 0.00426 (μmol−1ml s).

[S] μM	v0 (μmol ml−1 s−1)
320	169
160	132
80.0	92.0
40.0	57.2
20.0	32.6
10.0	17.5

a. Calculate Kcat for the reaction

b. Calculate Km for the enzyme

cWhen the reactions in part (B) are repeated in the presence of 12 μM of an uncompetitive inhibitor, the y-intercept of the Lineweaver-Burk plot is 0.352 (μmol−1 ml s). Calculate K′I for this inhibitor.

Answer 1