Ch 17: Lipids

1. Lipids: Water-insoluble biomolecules
   1. Lipids: water-insoluble biomoleculesj
2. Building blocks of saponifiable lipids
   1. Components of the head group: glycerol, phosphoric acid, ethanolamine, choline, and/or carbohydrates
   2. Other Components
      1. Fatty acids, nonpolar ("hydrophobic") tails
      2. Sphingosine, another lipid building block
      3. Waxes (a class of saponifiable lipids)
3. Saponifiable Lipids
   1. Triglycerides: glycerol + 3 fatty acids
   2. Reactions of Triglycerides (Fats and Oils)
      1. Saponification (ester hydrolysis under basic conditions)
      2. Addition of H₂: Hydrogenated fats
      3. Oxidation: Contributes to rancid fats/oils
   3. Phosphoglycerides: glycerol + 2 fatty acids + phosphoric acid + ethanolamine or choline, etc.
   4. Sphingolipids: sphingosine + fatty acid and/or phosphoric acid and/or choline and/or carbohydrate
      1. Sphingolipids are components of some cell membranes
4. Non-saponifiable Lipids
   1. Steroids
   2. Bile salts
5. Monolayers, micelles, bilayers, and cell membranes
   1. Monolayer: can form at polar/non-polar interfaces
      1. Monolayer and micelle
      2. Video:a fatty acid on water (no sound)
   2. Micelle: a sort of spherical monolayer
   3. Bilayer: serves as a boundary between two water regions
   4. Cell Membrane: a complex bilayer