1.2.2 Lipids(including mainly g! ycerophospholipids甘油裤脂)2 sphingolipid and sterols ) are the major structural elements or s, the biomembranes 1.2.3 The water-insoluble vitamins like vitamin A, D, e, k and some hormones (like steroids(类醇), prostaglandins(前列腺素)) are lipids 1. 2. 4 The bile acids help to solubilize(emulsify other classes of lipids for better digestion. 1. 2. 5 Lipids also serve as enzyme cofactors light-absorbing pigments, intracellular messengers.1.2.2 Lipids (including mainly glycerophospholipids （甘油磷脂）, sphingolipids, and sterols) are the major structural elements of the biomembranes. 1.2.3 The water-insoluble vitamins like vitamin A, D, E, K and some hormones (like steroids（类固醇）, prostaglandins（前列腺素）) are lipids. 1.2.4 The bile acids help to solubilize (emulsify) other classes of lipids for better digestion. 1.2.5 Lipids also serve as enzyme cofactors, light-absorbing pigments, intracellular messengers