Lipid Classification

LIPIDS
• A class of biological molecules (i.e., are of biological
origin) defined by low solubility in water and high
solubility in non-polar solvents (such as chloroform)
• They are largely hydrocarbon in composition, thus
• represent highly reduced forms of carbon, and
• upon oxidation in metabolism, yield large amounts
of energy.
Examples of LIPIDS:
• FATS and OILS,
• certain VITAMINS & HORMONES, and
• most NON-PROTEIN MEMBRANE COMPONENTS.
Lipids, per se, are not bad; they are indispensable to
metabolism & cell structure.
Section 9.1: Lipid Classification
*A. Fatty acids - get the picture & know some examples
*B. Triacylglycerols (see figures on p. 222)
C. Glycerophospholipids (= phosphoglycerides) —
the major lipid component of membranes (see Fig. 9-3)
D. Sphingolipids — major membrane C18 amino alcohol
E. Steroids — three 6-membered rings + one 5-membered
ring fused together---rigid; esp.important in diet/health:
*Cholesterol (Fig. 9.10)
F. Other — Waxes, terpenes, *Eicosanoids
*Know best: are health- and diet-related.