Simulating Dialysis: Simple Diffusion
Answers to Questions
Activity 1: Simulating Dialysis (Simple Diffusion) (pp. 2–4)
9. All solutes except albumin are able to diffuse into the right beaker.
Using distilled water in the right beaker and either the 100 MWCO or 200 MWCO membrane will remove urea from the left beaker and leave albumin
If the left beaker contains NaCl, urea, and albumin, you can selectively remove urea by dispensing a concentration of NaCl into the right beaker equivalent to that in the left beaker and by using the 100 or 200 MWCO membrane. Albumin is too large to diffuse and there will be no net diffusion of NaCl. However, urea will move down its concentration gradient into the right beaker.
Activity 2: Simulating Facilitated Diffusion (pp. 4–5)
11. Carrier …show more content…
7–9)
9. Smaller MWCO numbers translate to smaller pore sizes, which correlate with lower filtration rate.
Powdered charcoal did not appear in the filtrate using any membrane.
Increasing the force driving filtration increases filtration rate.
Increasing the pressure gradient effectively increases the filtration rate.
By examining the filtration results, we can predict that the molecular weight of glucose must be greater than NaCl but less than powdered charcoal.
Activity 5: Simulating Active Transport (pp. 10–11)
7. Solute transport stops before the completion of transport because of a lack of
ATP.
Sodium and potassium transport will not occur if ATP is not available.
8. Yes, transport has changed because more ATP is available. This fact supports the earlier supposition that ATP is required for active transport.
The rate of active transport will decrease if fewer solute pumps are available, but will still go to completion given enough ATP and time.
You can show that this is an active process by making the sodium concentration in the right beaker greater than the sodium concentration in the left beaker. Transport will occur against the concentration gradient in active transport but not in
Activity 1: Simulating Dialysis (Simple Diffusion) (pp. 2–4)
9. All solutes except albumin are able to diffuse into the right beaker.
Using distilled water in the right beaker and either the 100 MWCO or 200 MWCO membrane will remove urea from the left beaker and leave albumin
If the left beaker contains NaCl, urea, and albumin, you can selectively remove urea by dispensing a concentration of NaCl into the right beaker equivalent to that in the left beaker and by using the 100 or 200 MWCO membrane. Albumin is too large to diffuse and there will be no net diffusion of NaCl. However, urea will move down its concentration gradient into the right beaker.
Activity 2: Simulating Facilitated Diffusion (pp. 4–5)
11. Carrier …show more content…
7–9)
9. Smaller MWCO numbers translate to smaller pore sizes, which correlate with lower filtration rate.
Powdered charcoal did not appear in the filtrate using any membrane.
Increasing the force driving filtration increases filtration rate.
Increasing the pressure gradient effectively increases the filtration rate.
By examining the filtration results, we can predict that the molecular weight of glucose must be greater than NaCl but less than powdered charcoal.
Activity 5: Simulating Active Transport (pp. 10–11)
7. Solute transport stops before the completion of transport because of a lack of
ATP.
Sodium and potassium transport will not occur if ATP is not available.
8. Yes, transport has changed because more ATP is available. This fact supports the earlier supposition that ATP is required for active transport.
The rate of active transport will decrease if fewer solute pumps are available, but will still go to completion given enough ATP and time.
You can show that this is an active process by making the sodium concentration in the right beaker greater than the sodium concentration in the left beaker. Transport will occur against the concentration gradient in active transport but not in