CHAPTER 23 LIPIDS 23.1 INTRODCTION Lipids are compounds of biological origin that dissolve in pl nonopoler solvents Lipids are defined by the physical operation that we use to isolate themCHAPTER 23 LIPIDS 23.1 INTRODCTION Lipids are compounds of biological origin that dissolve in nonopoler solvents. Lipids are defined by the physical operation that we use to isolate them