Eggsperiment Write Up

Egg-speriment Write-up

Part 1- Purpose: Why did we do the experiment?

The purpose of this experiment was to understand how osmosis works and that the cell membrane is selectively permeable. Osmosis is the diffusion of water molecules through a selectively permeable membrane. Many cells cannot function without adequate water, so cells depend on osmosis. When a cell is selectively permeable, it means some substances can pass through while others can't. Many examples of these were shown throughout the experiment.

Part 2- Experiment Design: How did we do the experiment?
We did this experiment by starting out with a regular egg. We measured it by wrapping a string around the egg and measuring the length to find the circumference. We took the egg and put it in 100 mL of a particular liquid (this was the manipulated variable in the experiment). After letting it soak for two days, we remeasured the circumference. We repeated this multiple times with different liquids and recorded the data each time. We would also record the amount of liquid leftover in the cup using a graduated cylinder for most of the labs.

Part 3- Data Tables and Predictions see attached pages

Part 4- Analyze the Data see attached pages

Part 5- Conclusion: What was your conclusion of the experiment?
My experiment worked out the way I thought it would. My predictions were correct. My last prediction is debatable, for it did get bigger and harder. Although, it may not have gotten hard from the salt water. Throughout the experiment, the egg grew smaller and bigger. This was because different substances react differently to the egg. Some substances would go in while others wouldn't. This is an example of how a cell is selectively permeable. In the lab, there were possible sources of error. When we were measuring the circumference of the egg, we used string. Some people may have stretched the string out resulting in a vary of incorrect results. Also, the volume measurements