Osmosis in Cell Membranes

                                                                Jordyn, Ellie, Sarah

Title:

How Certain Substances Effect the Size of the Egg

Purpose:

To observe hypertonic and hypotonic.

Variables:

Independent- liquids

Dependent- egg growth

Controlled- Time, cups, environment, egg type, amount of liquid

Control Group- egg in water

Experiential- eggs in different substances

Hypothesis:

The egg in water will grow, the egg in corn syrup will shrink,  the egg in the oil will grow, the egg in the nail polish remover will shrink.

Materials:

eggs, cups, water, vinegar, corn syrup, nail polish remover, vegetable oil, tongs, paper towel, ruler

Procedure:

1) Put four eggs in vinegar for twenty-four hours so the shell dissolves off.

2) Carefully take the eggs out of the vinegar cups and dry them off, measure width of the egg.

3) Put the eggs back in cups filled with corn syrup, water, nail polish remover, vegetable oil and wait another twenty-four hours.

4) Take the eggs out of separate cups and measure the width again.

Observations:

After the vinegar cups, they're pink and look slightly bigger. The shells are dissolved in the vinegar, it looks like white foam surrounding the eggs. They float in the vinegar, and the outer layer is slightly see-through.

The eggs after being put in the liquids resulted in the changes below.

Results:

All eggs started with a measurement of two inches.
By the end, the measurements show as followed.

Corn syrup- 1 3/4 in. (Egg was hypotonic)

NPR- 1 3/4 in. (Egg was hypotonic)

Water- 2 1/2 in. (Egg was hypertonic)

Veggie oil- 2 in. (The egg was isotonic)

Conclusion:

We were correct about the water, the nail polish remover, and the corn syrup, however, the veggie oil stayed the same when we thought it would grow. Possible sources of error include time, since we just played 24 hours by ear, so to speak. We thought the experiment was fun and taught how water and other substances pass through membranes. It does a great job of showing hypo and hyper tonic membranes.

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