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plot a Lineweaver-Burk problem

A) Using the data given in table below plot a Lineweaver-Burk plot

b) Determine the Km and Vmax for the three sets of data

c) Which inhibitor would the most effective at high substrate concentrations?

d) Explain you choice

Table 1 :
Kinetics data for an enzyme catalysed reaction with and without the presence of inhibitors :

[S] mmol/L : 1.67 - 2.50 - 5.00 - 10.00

Initial velocity of reaction (micromol/min) :

without inhibitior : 0.100 - 0.125 - 0.167 - 0.200

with inhibitor A : 0.083 - 0.106 - 0.149 - 0.185

with inhibitor B : 0.068 - 0.083 - 0.105 - 0.122

Solution Preview

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Solution
A. The Lineweaver-Burk plot is a plot of 1/V versus 1/S as demonstrated in the below equation. Please see the attached section on theory.

I have plotted in the Excel file. Please see attached.

B. I fitted 3 trendline equations for each case as below:
No inhibitor: y = 10x + 4
According to the above relationship, Vmax = ΒΌ = 0.25 (μmol/min)
KM = 10*Vmax = 2.5
Inhibitor A: y = 13.4x + 4.1
Vmax = 1/4.1 = 0.24 (μmol/min)
KM = 13.4*0.24 = 3.2
Inhibitor A: y = 13.0x + 6.9
Vmax = 1/6.9 = 0.14 (μmol/min)
KM = 13*0.14 = 1.8

C and D.
Note that V approaches Vmax very slowly so that it is extremely difficult to get experimental data that clearly shows what the value Vmax is, and consequently what KM is. Hence at high substrate concentrations, we would ...

Solution Summary

The solution provides 3-page explanations, instructions, and drawings in the attached files.

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