A Lineweaver-Burk question:Is it more accurate to estimate Vmax from [V] vs [S] curve, or from Linew

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Apr 12, 2016
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Is it more accurate to estimate Vmax from [V] vs curve, or from Lineweaver-Burk equation?

This is a question from Princeton Biochemistry Review book page 95 Chapter 4 Practice passage. In the passage, it says in second paragraph:

"Despite the advantages of this linear representation of enzymatic rate data, the Lineweaver-Burk plot introduces greater error when used to determine Vmax and Km. Thus, it is not recommended when highly accurate values of these kinetic parameters are desired.

Then question 1 is "Which of the following is the best estimate for the Vmax of the enzyme represented by Figure 1"

In figure 1, it contains both the [V] vs curve and Lineweaver-Burk representation. V vs S curve levels off between 40-45 umol/min; but y axis intersect at 0.01 (which correspond to 50 if using 1/Vmax)

The correct answer according to book is D (52 umol/min) instead of C (44 umol/min)

What I cannot understand is: the passage said specifically that L-B plot introduce greater error for determining Vmax. Why it still chooses Vmax value from L-B plot instead of V vs S plot?
 

5words

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Dec 31, 2016
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Go back an re-read the passage, obv what they are saying is that L-B is more accurate than traditional plot but still not the best.
 
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Apr 12, 2016
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Go back an re-read the passage, obv what they are saying is that L-B is more accurate than traditional plot but still not the best.

Thank you.
It seems that the second paragraph which I did not quote here did say something like it was difficult to curve fit V S data accurately. And the sentences I quote here shows there is error with L-B, which as you said, not the best.
Now I understand it a little better. Thanks!
 
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