Download Transfer of Materials Across Membranes

Transfer of Materials Across Membranes
Lab Summary
Part A.
My experiment:
After an hour
If I added iodine to the beaker
Iodine
Starch
Diffused through
Membrane
Yes
No
Glucose
Yes
Protein
No
Water
Yes
Experimental Evidence
Solution in bag turned black
Solution in beaker did not
turn black
Solution in beaker gave a
positive TesTape test
Solution in beaker gave a
negative Biuret test
The bag appeared fuller
1. Water, iodine, and glucose were small enough to pass through the dialysis membrane, but protein,
starch, and lipid were too large to pass through.
2. Yes, iodine and water were going into the bag at the same time glucose was leaving.
3. It is semipermeable or selectively permeable and regulates what can pass through.
4. high, low
5. It would have to rely on active transport to do this….probably in the form of exocytosis.
6. Rough sketch of graphs
Starch
Concentration
Glucose
Concentration
Time (min)
Time (min)
7. As salt water is added water moves out of the cell from a higher concentration to a lower
concentration. When distilled water is added, water moves into the cell from the higher
concentration to the lower concentration.
8. It has a cell wall so it would not explode in a hypotonic solution.
9. Water would leave the plants because you have created a hypertonic solution with no water.
Water would leave the cells where it is in high concentration to move outside the cells where it is
in low concentration.
10. These foods are preserved by the hypertonic solutions be it salt or sugar because when a bacteria
lands on the food all of its water leaves and the bacteria shrivels up and dies. Jerky, dill pickles.
11. Not really. Molecules never stop moving.
12. Potato 1 was in a hypotonic solution so water entered its cells increasing its turgor pressure and
making it feel stiff. Potato 2 was in a hypertonic solution so water left its cells decreasing its
turgor pressure and making it feel flimsy.
13. isotonic is test tube 3; hypotonic is test tube 1; hypertonic is test tube 2
14. omitted
15. water (OSMOSIS)
16. cesium & iron
17. palladium
18. barium
19. yes, even though the cell is in equilibrium molecules will continue to move. It will be an equal
movement in and out.
20. Hypertonic means that the solution has more solute and therefore less water than the cell; Isotonic
means that the solution has the same amount of solute and water as the cell; Hypotonic means that
the solution has les solute and therefore more water than the cell.
21. Hypotonic
22. Out of the bag
23. Into the bag
24. No net movement
25. Because the inside of the cell has more free water than outside of the cell, the free water will
move out of the cell causing the cell to shrink.
26. Because the cell membrane cannot withstand the pressure of the cell filling up with water in an
animal cell and the cell explodes. In a plant cell, the cell wall is very strong and prevents the cell
from exploding.
Pig Intestine
Sugar
Starch
Distilled water
Protein
Amino Acid
Turgor Pressure
Iodine