Egg Diffusion Lab

24 hour time lapse of our Egg Diffusion Lab. Egg on left in corn syrup, egg on right in DH2O pic.twitter.com/wdfujQyBXM

— Mr. Orre's Class (@OrreBiology) October 5, 2016

     In this lab we placed two different eggs of about the same size in deionized water and corn syrup to see the effects on the circumfrence and mass of the eggs. Both the eggs had their shells dissolved off in vinegar, so substances could leave and enter the egg.

     According to the class data, when the sugar concentration increased, both the mass and the circumfrence of the egg decreased. This is because the corn syrup is a hypertonic solution. There is more sugar, which is a solute, outside of the egg than inside of the egg, so water and solvents from inside the egg leave, making the egg smaller in size. According to www.exploratorium.edu egg white is about 90% water and corn syrup is about 25% water. Due to this the water moves from an area of high concentration to an area of low concentration to create equilibrium with the solute. This is an example of passive diffusion.

     As the external environment of the egg changed in terms of concentration of water and solute, the interal conditions of the cell changed as well. When the outside of the cell was highly concentrated with solute, the water diffused out from inside the cell, and when there was less solute outside (deionized water) the water diffused into the egg. And when the egg was put in vinegar, the shell was dissolved off, leaving only the membrane.

     The lab demonstrated the biological of diffusion, which we learned in class. The lab was a good way of showing how the concentration gradient can really affect the size of the cell. We learned how cell membranes don't allow large solute molecules through, which was shown to be true by the lab, as the corn syrup didn't enter the egg, only water came out.

      Fresh vegetables are sprayed with water at markets, to prevent them from drying out. The water gets absorbed into the vegetable, as there is probably more solute in its cells. When salt is sprinkled onto the road, plants along the road are dried out and dehydrated. Salt is a solute and since, there is a higher concentration of salt outside of the plant, water diffuses out of the plant cells, drying out the plant.

     Based on this experiment, I would like to test how much water a cell can hold before popping. I would also want to find a way to maximize the amount of water it can hold, or maximize the amount that the cell can shrink as water diffused out.