1. Describe two variables that affect the rate of diffusion.
Your answer:
Two variables that affect the rate of diffusion are the MWCO membrane and the solute concentration. Increasing the membrane size and solute concentration will also increase the average diffusion rate. Decreasing the membrane size and solute concentration will reduce diffusion rates and can even prevent all diffusion.
2. Why do you think the urea was not able to diffuse through the 20 MWCO membrane? How well did the results compare with your prediction?
Your answer:
The urea was not able to diffuse through the 20 MWCO membrane because the molecular weight was too high. For a molecular weight of 60.07, a larger membrane would need to be used. The results opposed my prediction because the urea did not diffuse at all. I predicted that it would diffuse, but very slowly.
3. Describe the results of the attempts to diffuse glucose and albumin through the 200 MWCO membrane. How well did the results compare with your prediction?
Your answer:
Attempting to diffuse glucose and albumin through the 200 MWCO membrane resulted in only glucose passing through the membrane. The same concentration was used for both solutes, but albumin could not diffuse. The results contradicted my prediction because glucose was the only solute to diffuse through the 200 MWCO membrane. I predicted albumin would diffuse.
4. Put the following in order from smallest to largest molecular weight: glucose, sodium chloride, albumin, and urea.
Your answer:
Sodium chloride, urea, glucose, albumin.
Review Sheet 2 Results
1. Explain one way in which facilitated diffusion is the same as simple diffusion and one way in which it is different from simple diffusion.
Your answer:
One way in which facilitated diffusion is the same as simple diffusion is that increasing the solute concentration will also increase diffusion rates. One way in which facilitated diffusion is different from simple diffusion is