3.1.3. Lipids

• Triglycerides

  Formed by the condensation of one molecule of glycerol and three molecules of fatty acid
• The R-group of a fatty acid may be saturated or unsaturated.

  • Saturated have straight chains
  • Unsaturated have bent chains; making it more mobile/fluid
• Ethanol Emulsion Test

  1. Liquid sample
  2. Add Ethanol
  3. Mix
  4. Add Water
  5. Mix

  • Cloudy white emulsion
• Lipids are only soluble in organic solvents
• Glycerol and fatty acids form what bonds?

  Ester bonds
• Triglyceride strucure for energy storage?

  Long hydrocarbon chains, C:H ratio

  • Stores more energy per gram
• Metabolic water


  Oxidation of C-H bonds releases large numbers of water molecules during respiration