| − | A '''Biological membrane''' is the thin layer that forms the outer boundary of a living cell or of an internal cell compartment. It consists of a [[lipid bilayer]], which is a double layer of [[phospholipid]], cholesterol, and glycolipid molecules.<ref>https://www.britannica.com/science/membrane-biology</ref> | + | A '''Biological membrane''' is the thin layer that forms the outer boundary of a living cell or of an internal cell compartment. It consists of a lipid bilayer, which is a double layer of [[phospholipid]], cholesterol, and glycolipid molecules.<ref>https://www.britannica.com/science/membrane-biology</ref> |