Osmosis

Furst, John-Nicholas

Osmosis Background: Osmosis is a type diffusion in which a solvent is diffused through a semi permeable membrane from a region of high concentration to a region of low concentration. The solvent flows from the side of the membrane where the solution is weakest to the side where it is strongest, until the solution on both sides of the membrane is the same strength (that is, until it reaches equilibrium).

Problem: What is the affect of a hypertonic cell environment verse a hypotonic cell environment?

Hypothesis: The egg in the hypotonic cell environment will get larger. While the egg in the hypertonic cell environment will shrink.

Materials: 2 fresh eggs Beaker of vinegar Beaker of karo syrup Balance String and a metric ruler

Procedure: First measure the circumference of the two eggs at the widest point using string to rap around the egg. Next measure the length of the string. Record this number as your “pre-vinegar circumference”. Next, take the mass of your eggs. Record this number as your “pre-vinegar mass.” Then soak the eggs in vinegar for 24 hours. After the eggs have been exposed to the vinegar rinse the eggs gently to remove any remaining shell. Repeat the measurements you made initially and record them again, this time as “post-vinegar circumference” and “post-vinegar mass.” Next place egg “A” into a small beaker and cover it with water. Label the beaker. Afterwards place egg “B” into a different beaker and cover it with karo syrup. Label the beaker. Let the eggs soak in the new liquid for another 24 hours. After the eggs have soaked for 24 hours, rinse the eggs gently, pat dry, and repeat the same measurements. Record your data.

Before: Egg A B

Mass (g) 85.2 71.1

Circumference 163 155

Mass (g) 54.6 78.1

Circumference 139 161

After: Egg A B

Comparision of Egg's Mass Throughout Osmosis

Comparision of Egg's Circumference Throughout Osmosis

90 80 70 60 50 40 30 20 10 0

160

155

Egg A Egg B

Circumference (mm)

Mass (g)

165

150

Egg A Egg B

145

140

135

130

Before Osmosis

After Osmosis

Before or After Osmosis

125 Before Osmosis

After Osmosis Before or After Osmosis

Results: Egg B grew in size while Egg A shrunk in size. This was due to the process of osmosis and the seeking for equilibrium. Conclusion: In conclusion my hypothesis was correct and Egg B grew is size because it was place in a hypertonic solution and the water around the egg moved into the egg, while Egg A shrunk in size because it was placed in a hypotonic situation where all of the water inside of it left the egg. These are perfect examples of osmosis.