Simple Chemistry problem, need help?

Question

Glucose is the major energy yielding nutrient for most cells. Assuming a cellular concentration of 1 mm (I think this means millimoles?), calculate how many molecules of glucose would be present in a hypothetical (and spherical) eukaryotic cell. (Avagadros number, the number of molecules in 1 mol of a nonionized substance, is 6.02 x 10^23)

The answer to the question is 3.9 x 10^10 molecules, but how do they get that answer? Thank You

V= 6.5 x 10^-14 how do i get the answer now?

Answer 1

You can't do this question unless they give you the volume or dimensions of a standard cell. At least I can't. :-)

If you did have, say, the diameter of a spherical cell, you could use ((pi)(r^3)/6) to find the volume. Convert the volume into liters (it's gonna be TINY) and divide the 1mm by that number. That will give you the number of millimoles of glucose in a cell. Convert that to moles (x1000), and then multiply that number times Avagodro's number, and it'll tell you how many glucose molecules are in the cell. Sorry I couldn't help you more!

Answer 2

You are correct that 1 mm = 1 millimolar = 1 millimole/L

What you do not give is the dimensions of the eukayotic cell. What is the diameter, radius? V = 1/6*pi*d^3 V = 4/3*pi*r^3. That will give you the number of L x 10^-n.

Answer 3

To calculate this you will need to know the volume of the liquid in the cell. When you know that then the equation becomes: Cell vol L X 1 mMol/L X 7.023X10^20 molecules/mMol = molecules in the cell.