Proteins and lipids make up the cell membrane. Only certain things can move through because cell membranes are mostly mad of lipids. Phospholipids are the most popular lipid in the membrane. These are made up of the outer and inner layers.
Cell membranes are composed of proteins and lipids. Since they are made up of mostly lipids, only certain substances can move through. Phospholipids are the most abundant type of lipid found in the membrane. Phospholipids are made up of two layers, the outer and inner layers.
