THIS CHAPTER IN CONTEXT

Lipid metabolism can be conveniently divided into degradative and synthetic reactions, mainly involving fatty acids, the building blocks of lipids such as triacylglycerols and membrane phospholipids. The catabolism of fatty acids, like the catabolism of carbohydrates (covered in Chapter 10) yields acetyl-CoA, which is further metabolized to yield free energy by the citric acid cycle (Chapter 11) and oxidative phosphorylation (Chapter 12). This chapter also presents the biosynthesis of fatty acids, which allows easy comparison to the pathway of fatty acid degradation and illustrates some similarities and differences between opposing metabolic pathways. The related pathways of ketone body and cholesterol synthesis are also included. In addition to the catabolic and anabolic chemical reactions that occur within cells, lipid metabolism involves the transport of lipids via lipoproteins, whose importance in disease is outlined at the start of the chapter.

	Exercises
Fatty Acid Metabolism Animated Exercise: Fatty acids are degraded for energy during beta oxidation, and built at the expense of ATP during fatty acid synthesis. Lipoproteins Animated Exercise: Lipoproteins are complexes of lipid and protein that transport cholesterol and other lipids between tissues. Related Links Chapter 14 Quiz Web Links Biomolecular Structures