Lipids are nonpolar substances. Because lipids are nonpolar compounds, they are soluble in nonpolar compounds, such as chloroform or benzene. However, lipids are not soluble in water because it is a polar compound.
Lipids are a group of substances that include fats, phospholipids, waxes and sterols. Fats consist of glycerol and fatty acids. A triglyceride is made up of glycerol and three fatty acids. Fats can also be categorized as either saturated or unsaturated fats. Another form of lipid is sterols, which consist of cholesterol and hormones.
A phospholipid's structure consists of two fatty acids and a phosphate group. Phospholipids are found in the cell membrane of animal cells. Plants and animals produce waxes, which are made up of one chain of fatty acids. In animals and plants, the main function of waxes is for protection.