Solute Potential of Cell Sap of Plant Epidermal Cells

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Solute Potential of Cell Sap of Plant Epidermal Cells

Aim: To estimate the solute potential of a plant tissue.

Results:

Molarity of Solution

Plasmolysed Cells

Percentage of Cells That Were Plasmolysed

.3M

1/70

.01%

.4M

0/70

0%

.5M

5/70

7%

.6M

12/70

17%

.7M

29/70

41%

1.0M

56/70

80%

It must be taken into account, that the experiments procedure was

changed. This could have had a great affect on the results. The part

of the procedure that was changed was the time. Instead of the

epidermal cells being left in the solutions 20 minutes, they were left

for a day. Not only, were they left much longer, but the molarity of

the solutions could have also changed since they were left uncovered

for over 24 hours and some of the water could have been evaporated.

Another factor that contributed to the errors in this investigation

was that all of the data was approximated. Every single cell that

appeared in the microscope was not accounted for and therefore all

collected data is not exact, but instead a rough calculation. Another

error that could have occurred, and that would explain what happened

to the cells that were put in the solution with .4M, is that onion

skin dried out before it was placed in the sucrose water. Also, there

could have been a variation between the different onion epidermis

cells that were used.

Conclusion:

The results of the investigation show that the greater the molarity,

the more plasmolysed cells will appear. Plasmolyses is the shrinkage

of volume of a cell. This is caused by the falling of water

concentrations and ultimately results in the contraction of the

membrane. The most contracted membranes were found in epidermal cells

that were left in the solution with the greatest molarity; in this

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