You design an experiment to test the effect(s) various compounds have on the osmotic potential of a model cell. You know that substances dessolved in aqueous or gaseous solutions tend to diffuse regions of higher concentration to regions of lower concentration.
You fill each of three (20 ml) dialysis bags half full with one of these substances:
* 5% by weight of glucose in distilled water
* 5% by weight of egg albumin (protein) in distilled water
* 5% by weight of glass bead (one glass bead) in distilled water
The dialysis bag is permeable to water but impermeable to glucose, albumin, and glass bead.
a. If the final weight of each bag is 10 g, how many grams of glucose, albumin, and glass bead were added to each bag?
b. The molecular weight of the protein is about 45,000 atomic mass units, and the molecular weight of glucose is about 180 atomic mass units. How can you estimate the number of molecules of glucose in the 5% solution compared to the number of albumin molecules in its 5% solution?
c. You put the dialysis bags into three separate flasks of distilled water. After 2 hours, you remove the bags and record these weights:
Dialysis Bags Weight
Glucose 13.2 g Albumin 10.1 g Glass bead 10.0 g
How do you explain these results? (Hint: Consider the surface area-to-volume ration of each of the three substances.
d. What results would you predict if you set up a similar experiment but used 5% glucose and 5% sucrose?
You design an experiment to test the effect(s) various compounds have on the osmotic potential of a model cell. You know that substances dessolved in aqueous or gaseous solutions tend to diffuse regions of higher concentration to regions of lower concentration.
You fill each of three (20 ml) dialysis bags half full with one of these substances:
* 5% by weight of glucose in distilled water
* 5% by weight of egg albumin (protein) in distilled water
* 5% by weight of glass bead (one glass bead) in distilled water
The dialysis bag is permeable to water but impermeable to glucose, albumin, and glass bead.
a. If the final weight of each bag is 10 g, how many grams of glucose, albumin, and glass bead were added to each bag?
b. The molecular weight of the protein is about 45,000 atomic mass units, and the molecular weight of glucose is about 180 atomic mass units. How can you estimate the number of molecules of glucose in the 5% solution compared to the number of albumin molecules in its 5% solution?
c. You put the dialysis bags into three separate flasks of distilled water. After 2 hours, you remove the bags and record these weights:
| Dialysis Bags | Weight |
| Glucose | 13.2 g |
| Albumin | 10.1 g |
| Glass bead | 10.0 g |
How do you explain these results? (Hint: Consider the surface area-to-volume ration of each of the three substances.
d. What results would you predict if you set up a similar experiment but used 5% glucose and 5% sucrose?
