Lipids

• Triglycerides:

  • 3 fatty acids
  • glycerol
• Phospholipids:

  • 2 fatty acids
  • glycerol
  • phosphate group
• Phospholipids consist of a hydrophilic head and a hydrophobic tail.
• Lipids are joined by ester bonds which are formed by condensation reactions.
• Emulsion Test:

  • Dissolve food sample in ethanol.
  • Add water to mixture and shake.
  • Presence of lipids will be indicated by a milky white emulsion.
• The R-group of a fatty acid may be saturated or unsaturated.
• Roles of lipids:

  • Source of energy
  • Waterproofing
  • Insulation
  • Protection
• Fats are solids at room temperature ( 10 - 20 C ) whereas oils are liquids.