Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

The velocity of an enzymatic reaction (expressed in nmoles x liter^-1 Times min^

ID: 1010669 • Letter: T

Question

The velocity of an enzymatic reaction (expressed in nmoles x liter^-1 Times min^-1) for different concentrations of substrate (S, expressed in moles Times liter^-1)) are summarized in the following table. The Hanes-Woolf plot represents [S]/v (y axis) versus [S] (x axis). Rearrange the Lineweaver-Burk to determine the linear equation for the Hanes-Woolf plot (y = ax + b, with y= [S]/v and x = [S]). What do the intercepts with the [S]/v and the [S] axis, and the slope of the straight line represent? (For example in the Lineweaver-Burk plot, the intercept of the straight line and the y-axis represent 1/Vmax) The Woolf-Augustinsson-Hofstee plot represents v versus v/[S]. Rearrange the Henri- Michaelis-Menten equation to determine the linear equation for the Woolf-Augustinsson- Hofstee plot. What do the intercepts with the v and the v/[S] axis, and the slope of the straight line represent? Compare the numerical values of Km and Vmax calculated from each plot.

Explanation / Answer

Q.1: The equation for Hanes-Woolf plot is

([S] / v) = ([S] / Vmax) + (Km / Vmax)

y = mx + c

Slope of the above equation of straight line represents 1 / Vmax, i.e m = 1 / Vmax (answer)

Y - intercept([S]/v) = Km / Vmax

X - intercept([S]) = - Km

Q.2: Woolf-Augustinsson-Hofstee plot is

v = - Km x (v / [S]) + Vmax

Slope of the above equation of straight line represents - Km, i.e m = - Km (answer)

Y - intercept(v) = Vmax

X - intercept(v / [S]) = Vmax / Km

Q.3: