Eggs are the perfect example of a simplified cell. And they are pretty easy to come by in the average family fridge. Welcome to a great at home science lab.
In sixth grade life sciences, students gained valuable lateral thinking skills using the perfect prop to observe and reflect on cellular processes. It's one thing to learn about these processes from a textbook, it's another thing entirely to observe them close up in your own remote science lab (also known as the kitchen).
In order to observe cellular processes, students had to first remove the shell, exposing the cell's semi-permeable membrane.
With the membrane exposed, students conducted two experiments:
- Diffusion—by submerging the egg in corn or maple syrup students could observe that the syrup molecules were unable to penetrate the cell's membrane, but the smaller molecules within the cell diffused out, making the egg appear to deflate.
- Osmosis—by sinking the egg into water treated with food coloring, students saw that the egg inflated and turned the color of the water, showing that the molecules of the colored water moved through the membrane.
Students evaluated the effects of each experiment by measuring the change in the egg's circumference with dental floss, or ribbon, or string (any yarn-like material available at home).
Teacher Andrea Vode had students do the experiment first and only then did she introduce the vocabulary. "I had students come up with analogies for the cellular processes we just observed," she said, an exercise in critical thinking that brings all of the learning together.
"My home," one student wrote, "my mom is the nucleus, she controls the functions of the home." Another student said it was like Disney World, "the ticket gate is like the cell membranes controlling who enters and leaves the cell." And still another student associated specific organelles to a baseball team, "the closer is like the lysosomes, they clean up the game."