Section Bank C/P Q30

[taylorswift132]

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Can't seem to figure out what's going on here. Km = 1/2(Vmax) and from the graph, it looks as though Vmax = 1.6. Why is the answer 1.31?

 

[theonlytycrane]

Km is the substrate concentration when v = 1/2 vmax.

So it's the substrate concentration, not the vmax velocity.

 

[DrMantisTobogganMD]

Km = CONCENTRATION of substrate at 1/2 Vmax. Vmax is roughly 1.5, half of that is roughly 0.75 uM/s. Concentration at that velocity is roughly 1.3

Edit: roughly

 

[laczlacylaci]

You could have also easily gotten the answer by looking at the formula.
v=S*Vmax/Km+S
(S=substrate concentration)

therefore Vmax=1.732 & Km=1.310

If you were in a rush, it might be hard to distinguish between 1.7 and 1.3 on that graph.

 

[taylorswift132]

Ah such a silly mistake! Thanks everyone!