Student 1 Lab Report
Dr. Newton
10/18/12
Lab Report Plasmolysis in Elodea Leaves
Introduction
The purpose of this lab was to induce what concentration of NaCl causes plasmolysis in Elodea
leaves. I believe that any concentration of NaCl solution will cause the Elodea leaf to undergo
plasmolysis, however I also believe the higher the concentration, the more evident plasmolysis
will be. Therefore my hypothesis is the five percent dilution of 1.0M NaCl will be enough to
cause the Elodea leaves to undergo plasmolysis. To complete this lab successfully, I will need a
microscope, wet mount cover slips, water, table salt, Elodea leaves, pipettes, beakers, gram scale,
graduated cylinder, and a stop watch.
Methods
Elodea was purchased at PetSmart and kept in tap water until the experiment. We used iodized
table salt from a local grocery store to make the solutions. The rest of the materials were
provided to us in the lab. The first thing my group members and I did was calculate the amount
of NaCl that would make the Elodea undergo plasmolysis. Those calculations are down below.
To dilute the stock solution of 1M down to 0.5M, We had to take 2.5mL of the stock solution
and add 2.5mL of water. To make 0.1M solution, we took 0.5mL of the stock solution and
added 4.5mL of water. To make 0.05M solution, we took 0.25mL of stock solution and added
4.5mL of water. After we made all of our dilutions, We took three pieces of Elodea leaves for
each test, 18 pieces in total, and put three drops of solution in a wet mount along with the leaf
and looked through the microscope to see if and how long it took for the leaf to undergo
plasmolysis, recorded the time it took with a stopwatch and repeated each trial three times for
each solution.
 Dilutions
1 : 1M(V1)/1M = 0.5M(5mL)/1M
V1 = 2.5mL , Water = 2.5mL
2 : 1M(V1)/1M = 0.1M(5mL0/1M
V1 = 0.5mL , Water = 4.5mL
3 : 1M(V1)/1M = 0.05M(5mL)/1M
V1 = 0.25mL , Water = 4.75mL
Results
1M NaCl Solution 0.5M NaCl Solution 0.1M NaCl Solution 0.05M NaCl Solution 0M NaCl Solution (control) Test 1 Yes, immediately Yes, 30 seconds Yes, 75 seconds Yes, 90 seconds No Conclusions/Discussions
Test 2 Yes, immediately Yes, 25 seconds Yes, 80 seconds Yes, 115 seconds No Test 3 Yes, immediately Yes, 20 seconds Yes, 70 seconds Yes, 100 seconds No We saw that all solutions caused plasmolysis in the Elodea leaves except for the control.
The major difference between all the trials was the amount of time it took for plasmolysis to take
place depending on the concentration of the solution. The less salt concentration the solution
had, the longer time it took for plasmolysis to take place. In conclusion, I believe that the 1M,
0.5M, 0.1M, and the 0.05M NaCl solution caused plasmolysis because the salt concentration in
the solution was greater than the salt concentration inside the leaf. It created a hypertonic
environment for the leaf.