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. Now, the type of structure that is formed depends on the type of lipid molecule that we have in the aqueous environment. And we'll see why in just a moment. So when certain lipids are placed into water, they will spontaneously rearrange themselves to form structures called MiCell.