And what you’ve all been waiting for
Using the equation governing the flow of sugar across a membrane:
and given that
The area of the membrane between the two solutions is 2 cm2
The concentration of the solution on the left side of the membrane = 0.4 M
The concentration of the solution on the right side of the membrane = 0.1 M
P= 0.02 cm/sec
What is the rate of diffusion (flow rate) across the membrane for the following concentrations?
This kind of problem requires straightforward substitution…
0.02cm/sec x 2 cm2 x (0.4 M sugar – 0.1 M sugar)
The flux (flow rate divided by the area) would therefore be 0.012 / 2 = 0.006 mol cm -2 s -1
What would happen if we doubled the permeability constant?
What if we doubled the area of the membrane?
What if we doubled the concentration on the left?