11.1: Fatty Acids Fatty acids are carboxylic acids that are made up of 12 to 20 carbons. They are building blocks of waxes, triglycerides, and membrane lipids. 11.2: Ester Formation and Waxes Esters are made by the reaction of a carboxylic acid with an alcohol, a process that is called esterification. Waxes are formed from long chain fatty acids and long chain alcohols. 11.3: Triglycerides- Fats and Oils Fats and oils are molecules known as triglycerides, which are esters of three fatty acids and glycerol. 11.4: Oxidation and Reduction Reactions of Triglycerides The oxidation of the alkene functional group in a triglyceride can form compounds with a disagreeable odor. The double bonds present in unsaturated triglycerides are partially hydrogenated to convert oils to a semisolid product like margarine. 11.5: Neutralization of Fatty Acids and Hydrolysis of Triglycerides Fatty acids can react with bases to form an amphipathic compound called soap. Soaps are made by the hydrolysis reaction of a triglyceride with an aqueous solution of a base. 11.6: Steroids Steroids have a four-fused-ring structure and have a variety of functions. Cholesterol is a steroid found in mammals that is needed for the rigidity of cell membranes, synthesis of bile salts and steroid hormones. 11.7: Amphipathic Lipids and Membranes The membrane lipids are amphipathic lipids such as phospholipids, glycolipids, or sphingolipids. Proteins are another important component of biological membranes. Deposits of cholesterol adds rigidity to the membrane. 11.8: Transport Across Cell Membrane There are three different ways molecules and ions move across a cell membrane. They are diffusion, facilitated diffusion, and active transport. Active transport requires energy, while diffusion and facilitated diffusion do not. Most polar molecules and ions require a protein channel during transport. 11.9: Digestion of Triglycerides Bile salts help to emulsify the hydrophobic triglycerides in the aqueous gastric solution. The enzyme lipase catalyze the hydrolysis (digestion) of the triglycerides to fatty acids and monoglycerides. 11.10: Fatty Acid Catabolism Fatty acids, obtained from the breakdown of triglycerides and other lipids, are oxidized through a series of four reactions in a spiral. The products of the spirals are processes by the citric acid cycle, the electron transport chain, and oxidative phosphorylation to produce ATP. 11.11: End of Chapter Problems This problem set is based on Chapter 11 topics.