Membranes are complex structures composed of lipids, proteins, and carbohydrates. The major membrane lipids are phospholipids, glycosphingolipids, and cholesterol. Membrane phospholipids are broadly of two types: phosphoglycerides, which are relatively more abundant, and sphingomyelins, which is prominent in myelin sheath. Membrane glycosphingolipids include cerebrosides and gangliosides.

Both are derivatives of sphingosine.