Potato Osmosis Lab Report

Sophie Murdock
Osmosis Lab

Osmosis in Plant Cells:

Solution
Initial Volume (mL)
Final Volume (mL)
Percent Change
Distilled Water
0.8
1.0
125%
0.4% NaCl
0.5
0.8
160%
0.9% NaCl
0.6
0.8
133%
5% NaCl
0.6
0.5
83%
10% NaCl
0.6
0.5
83%

8. The cells in the solutions of distilled water, 0.4% NaCl, and 0.9% NaCl would all appear to be inflated and could burst. This is due to the fact that the solution is hypotonic to the potato, thus water is entering the cell. Meanwhile, the cells in the solutions 5% NaCl and 10% NaCl would have shriveled cells. This is because the solution is hypertonic and water is leaving the potato out into the solution.

Record the Lysis Time:

Solution
Lysis Time (min)
DI
1:36
Soapy Water
0:48
0.2% NaCl
4:30
0.4% NaCl
NL
0.6% NaCl
NL
0.9% NaCl
NL
2% NaCl
NL
5% NaCl
NL
*NL means that no lysis was experienced

2.
In the 5% NaCl solution, the cells were observed to undergo crenation. In this process, the cells are in a hypertonic solution so the water transfers from the cell out into the solution. This transfer causes the cells to shrink and appear to shrivel. Meanwhile, in the distilled water the cells were observed to lysis and rupture. In this process, the cells are in a hypotonic solution, causing the water to rush from the solution into the cells. This movement of water causes the cells to swell until they eventually burst or lyse.

3. Both the solutions of 0.2% NaCl and soap-filled water experienced lysis but at different rates. The mechanism of the 0.2% NaCl solution is osmotic movement of water into the cells, due to the cell being a hypotonic solution. Meanwhile, the soap solution undergoes another mechanism of lysis. The detergent from this solution causes a disruption of the lipid matrix of the cell membrane, resulting in the lysis.

4. Due to the solutions being hypertonic compared to the cell, the solutions of 2% NaCl and 5% NaCl would result in crenated
cells.

5. Out of the solutions used, the 2% NaCl and 5% NaCl would be categorized as hypertonic. Meanwhile, the distilled water, 0.2% NaCl, and 0.6% NaCl would be hypotonic solutions.

6. The solution that would be the best for an intravenous injection would be the 0.4% NaCl solution because it is an isotonic solution and would not cause a change in the cell size.

Molecular Size and Cell Permeability:

Solution
Lysis Time (min)
Urea (60 MW)
6:00
Glucose (92 MW)
NL
Sucrose (342 MW)
NL
*NL means that no lysis was experienced

2. Some hypertonic solutions are able to cause lysis because smaller molecules in some solutions can diffuse though the membrane down the concentration gradient, causing water to flow into the cell and lysis to occur.

3. Molecular weight affects the movement of molecules through membranes because membrane pores only allow smaller molecules to enter, thus not letting larger molecules to move across the membrane. This causes molecules with larger molecular weights to be too large to diffuse through the membrane.