If 5 molecules of a particular protein were present in an E. coli cell, what wou
ID: 1022807 • Letter: I
Question
If 5 molecules of a particular protein were present in an E. coli cell, what would be the nanomolar concentration of this protein? Assume an E. coli cell to be a cylinder 2.2 micrometers long and 1.09 micrometer in diameter. Report your answer to the nearest tenth of a unit, and for a hint, see the handout entitle Equations, Math Concepts, and Conversions on Canvas. Please note that the units are understood to be nanomolar (or nM), but just enter the numerical answer and not the units. I do not want people to miss this question because one person used "nanomolar" and another person used "nM".
Explanation / Answer
we have to find out
the volume of the E.coli cell = pi x r^2 x h= 3.14 x ( 1.09 / 2 )^2 x 2.2 mm3
= 2.0525 mm3
we have = 5.0 molecules per 2.0525 mm3
= 2.436 x 10^15 per dm3
Divided by avagadro's constant:
we get
molar concentration = 2.436 x 10^15 per dm3 / 6.023 x 10^23 per mol
= 4.0 x 10^-9 mol/dm3
= 4.0 nanomolar
or = 4.0 nM