18. An experiment was performed to determine the effects of an inhibitor on the

Question

18. An experiment was performed to determine the effects of an inhibitor on the breakdown of glycogen by an enzyme. In an accompanying experiment, the inhibitor was added to the glycogen-enzyme suspension and reacted using the same experimental conditions. The data obtained from these experiments is tabulated below. Glycogen (mM) 0.5 1.0 1.5 2.0 2.5 3.0 Product Formed Glycogen only (mM/min) 22.6 32.1 38.1 41.2 44.7 48.5 Product Formed Glycogen and Inhibitor (mM/min) 15.9 24.9 28.2 35.1 40.0 43.3 (6 marks) Draw the Michaelis-Menten and Lineweaver-Burke plots of these data. a.

Explanation / Answer

Michaelis-Menten kinetics is

V= VmaxS/(KM+S) and hence a plot of rate, V( on y-axis ) and S ( concentration of glycohen)( on x-axis) is drawn and shown below

in case of Lineweaver-burk plot, 1/V= (KM/Vmax)*1/S+ 1/Vmax

so a plot of 1/V vs 1/S gives a straight line whose slope is KM/Vmax and intercept is 1/Vmax.

from the plot, 1/Vmax= intercept = 0.016 with and without inhibition= 62.5 mM/min

when there is no inhibition, Slope is KM/Vmax= 0.013, KM= 0.013*62.5 =0.8125 mM

when there is inhibition, slope is KMapp/Vmax= 0.023, Km=0.023*62.5= 1.4375 mM

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.