Cell membranes are made up of chemical components such as lipids, proteins, and sugars. Lipids (mainly phospholipids), proteins and sugars make up the cell membrane, and proteins as well as lipids are the main components. Under the electron microscope, the cell membrane is divided into three layers, with an electron-dense band of about 2.5 nm thickness on each side, and a transparent band of about 2.5 nm thickness between the two, making the cell membrane about 7.0~7.5 nm thick. The basic scaffolding of the cell membrane is a phospholipid bilayer, some lipids are combined with sugars to form glycolipids, and some proteins are combined with sugars to form glycoproteins. The function of the cell membrane is the contact between the cell and the outside world, as well as the cell for material exchange. Therefore, a stable cell membrane is the basis for the cell to perform normal physiological functions.