[icyhead]

Hi, I've a tedency to confuse myself with moles, so if someone can check my calculation that would be really helpful. Thanks

Heres the question
The enzyme quinol (bo3) oxidase [Molecular Weight 140 000Da] was isolated
from Escherichia coli and analysed for its metal composition using Atomic
Absorption Spectroscopy. Qualitative analysis indicates the presence of both
iron (Fe) and copper (Cu). Using electronic absorption spectroscopy, an
absorbance of 1.895 units is detected at 407nm typical of haem Fe. The
concentration of haem Fe in the enzyme is subsequently determined in a 1 ml
sample containing 1.4μg of enzyme.

(b) Calculate the concentration of oxidase in solution (in μM).

MW = 140000 and I have 1.4 ug, aka 1.4x10^-6 g
so 1.4x10^-6 /140000 = 1.4x10^-11 Moles
Its in 1 ml so  x by 10^3  = 1.4x10^-8 Mol/L
then to get in uM x by 10^6 = 1.4x10^-2 uM

[icyhead]

Just gonna *Ignore me, I am impatient* it once, incase anyone willing to help missed it.