Membrane Models

Today in my Living Environment class, we started talking about cell membranes and the idea of them being selectively permeable.  Since we can't actually see the structure of the lipid bilayer, we built it.  We talked about the hydrophilic heads and the two hydrophobic tails of each phospholipid. We also talked about the proteins embedded in the bilayer that allow molecules through that couldn't otherwise pass through the bilayer.

Each student had a slightly different vision of their membrane. We had some very spread out phospholipids and some very tightly packed ones. Some were more fluid than others. The idea came from a pin on Pinterest.  It was just a pin of a picture, so I'm not sure who to attribute it to.  I typed up a version of the activity for my students based on the picture.  I just made it on a half page, so it would fit easily in their notebooks.  

This bilayer got squeezed into one layer. Oops!

We capped the class off with our diffusion and osmosis lab, so they could see the actual movement of molecules across a membrane.