Lipid Bilayer: A thin membrane made of two layers of lipid molecules. These membranes are fluid and form spontaneously in an aqueous environment due to their hydrophobic nature.
Phospholipids: A type of lipid molecule that is a major component of all cell membranes as they can form lipid bilayers because they have both hydrophilic (head) and hydrophobic (tail) properties.
Hydrophobicity: The physical property of a molecule that is seemingly repelled from a mass of water.