Egg Diffusion Lab

In this lab we wanted to further explore how diffusion works, and we wanted to find out how and why a cell's internal environment changes when its external environment changes? We first took two eggs and soaked them in vinegar for 24-48 hours. After this amount of time, the calcium carbonate shell had been dissolved by the acetic acid. After washing and recording the mass and circumference of the eggs, one egg was placed in deionized water and the other was placed in sugar water. We let the eggs sit for 24-48 hours, and then recorded the new circumference and mass.

When the sugar concentration of the solution increased, the mass and circumference of the egg decreased, and the egg began to look shriveled up. The mass of the egg in sugar water decreased on average by 47.25% and the circumference decreased on average by 22.94%. In the egg that was placed in deionized water, the sugar in the macromolecules were the solute inside of the egg and water was the solvent outside. From a desire to reach equilibrium, the solvent wanted to move by diffusion from a low concentration of solute (outside cell) to a high concentration of solute (inside cell). Therefore, the cell gained water and grew. This is an example of a hypertonic solution.

It is desirable for cells to have an equal concentration of solute and solvent inside and outside of the cell. The cell membrane is semi-permeable and does not allow for the solute to leave the cell or enter the cell. The conditions of the cell are only changed by the movement of solvent. This is an example of passive diffusion. The cell expanded when put in vinegar, it shrunk when put in sugar water, and it grew when put in water.
In class we have learned about molecules which move from a high concentration to low concentration when there is an unequal concentration of solute or solvent.

Since cells grow when they are put in water, fresh vegetables in markets will be sprinkled with water to keep them fresh and help them to not shrivel up. Salt is sometimes sprinkled on roads to melt ice because since salt is a solute, the ice (which is water and is a solvent) the solvent will move outside and in order for it to do this it must melt. However, if the salt is sprinkled along the roadside where there are plants, the plants will die. This is because the plant cells will shrink when exposed to too much salt, and when they shrink, they will not function as well.

I would like to see the effect of putting salt on plants in action and other such experiments that illustrate cells shrinking due to too much solvent. Also, I would like to know if the shriveled up egg was placed back in deionized water, how long would it take to be revived?

Data Table for Eggs in Deionized and Sugar Water

Top: Egg that was placed in sugar water
Bottom: Egg that was placed in deionized water