Lipids

• Lipids are made up of the elements:

  • Carbon
  • Hydrogen and
  • Oxygen.


  Fats are solid at room temperature and oils are liquid at room temperature.

  True lipids (Triglycerides)- are formed from three fatty acids and one glucerol.
• Lipids are polymers of fatty acids and glycerol.

  Fatty acids -are a series of acids.

  -have the general formula

  CH3(CH2)nCOOH.

  -have a long hydrocarbon chain.

  Based on the presence or absence of double bond, there are two types of fatty acids.

  1. Saturated fatty acid
  2. Unsaturated fatty acid.

  Saturated fatty acid:

  • Have no double bond in their C-C chain.
  • All saturated fatty acids are solid at room temperature.
• Unsaturated fatty acids:

  • Have one or more double bond(s).
  • Doubel bonds make lipids melt more easily.
  • Don't contain the maximum amount of hydrogen.
  • There are two types of unsaturated fatty acids.

  1. Mono unsaturated fatty acids.
  2. Poly unsaturated fatty acids.


  Mono unsaturated fatty acids:

  _have only one double bond.

  Poly unsaturated fatty acids:

  _have two or more double bonds.
• Where is fat stored in our body?

  • Adipose tissues
  • Cell membrane
  • Brain and nervous system

  Phospholipids-

  • Are subset of lipids.
  • Each molecules has the usual property of having one water soluble.
  • One of fatty acid is replaced by Phosphate group which is polar and thus dissolve in water.
  • Have polar heads and non polar tails.
  • Exhibits dual characteristics.
• Hydrophilic head:(Water loving)-

  -The phosphate group makes the head which is polar.

  Hydrophobic tail:(Water hatring)-

  -The two remaining fatty acid tails.

  Major functions of lipids:

  • Serve as the foundation for other lipids.
  • Serve as major fuel stores.
  • Serve as structural components in cell membrane.
  • Serve as protective coating.