Question

4. The following data were obtained from an enzyme kinetics experiment. Graph the data using a Lineweaver-Burk plot and determine, by inspection of the graph, the values for Km and Vmax. ISI (M) V (nmol/min) 0.20 0.26 0.33 1.00 1.43 1.67 2.08 3.33 5. You measured the kinetics of an enzyme activity as a function of substrate concentration (see Table). The enzyme concentration was maintained constant at a level of 1 M. [S] AM Vopmol/min 2.9 3.8 4.4 Plot the data using the double-reciprocal (Lineweaver-Burk) plot. Determine Vm and K,

Answer 1

Question 4.

The graph of 1/[V] versus 1/[S] can be drawn as follows.

0.0007 0.0006 0.0005 1/V (min/umol) 0.0004 0.0003 11[S] (UM)

Equation of the plot: 1/V = 1.01307*10^-4*1/[S] + 1.94442*10^-4

Compare the above equation with Line-weaver Burk plot equation: 1/V = (K_M/V_max).1/[S] + 1/V_max

Then 1/V_max = 1.94442*10^-4 min/umol, i.e. V_max = 5142.9 umol/min or 5142.9 uM/min

Now, K_M/V_max = 1.01307*10^-4 min, i.e. K_M = 5142.9 umol/min * 1.01307*10^-4 min = 0.521 umol or 0.521 uM