Chapter 4 - Membrane Lipids: Fatty Acids

Abstract

“Lipid” is derived from the Greek word lipos meaning “fat.” Therefore, lipids are by definition insoluble in water but soluble in nonpolar organic solvents. Water insolubility is conferred via lipid molecular structure, having large regions of the surface composed of hydrocarbons with very few polar groups. A subset of lipids, those of interest in membrane studies, are structurally schizophrenic, containing segments that are polar and so prefer dissolution into water and more extensive regions that are totally nonpolar and avoid water at all cost. These lipids are referred to as “amphipathic,” or containing both hydrophobic and hydrophilic moieties (Fig. 3.7), and are the focus of this book.