Lipids

• Uses of Lipids:

  • Energy source
  • Insulation
  • Waterproofing
  • Protection
  • Buoyancy
  • Makes up cell membrane
  • Attracts insects
• Triglycerides are formed by condensation of glycerol and fatty acid chains joined by ester bond.
• Saturated fatty acids:

  • Only single bonds between carbon atoms.
  • More number of hydrogen atoms with same amount of carbon atoms.
  • Straight chain.
  • Higher melting point.
• Unsaturated fatty acids:

  • Have at least one double bond between carbon atoms.
  • Less number of hydrogen atoms with same number of carbon atoms.
  • Bent chain.
  • Has a lower melting point.
• Phospholipids are esters of fatty acids and glycerol but with one fatty acid chain replaced by a phosphate molecule.
• Glycolipids have a carbohydrate forming the polar head.
• Wax are esters of long chain alcohol and fatty acids
• Cholesterol is alcohol with four rings that are joined to each other.
• Phospholipid structure