And it turns out that it's the amphipathic nature of lipids that gives them the propensity, the ability to actually form, form these cell membranes. So when we take a lipid molecule and we place it into an aqueous environment where water is a solvent, the polar water molecules will tend to form favorable interactions, hydrogen bonds with the polar region of that lipid. But the non polar hydrophobic section of that lipid will not want to interact with the water molecules. And so what happens when we place many of these lipids into an aqueous environment to basically stabilize that system, to create a system, a structure that is lower in energy, they will spontaneously rearrange themselves and form these structures. And we have two types of structures that they can form. We can form micelles or we can form the bimolecular sheet, the lipid bilayer, which basically is the cell membrane that is found around the eukaryotic cells of our body.