Lipids

• Structure of Triglycerides


  • Made of Fatty Acids and Glycerol
  • Glycerol is a 3 carbon molecule with 3 alcohol groups
  • Fatty Acids are long molecules with a polar hydrophilic end, and non polar hydrophobic “tail”. The hydrocarbon chain can be 14 - 22 CH2 units long, but has to be an even number because of the way fatty acids are made
• Uses of Lipids


  • Source of energy
  • Waterproofing
  • Insulation
  • Protection
• Fatty Acids can be…


  Saturated or Unsaturated

  • Unsaturated Fatty Acids have a double carbon to carbon bond
  • Polyunsaturated Fatty Acids have multiple double carbon to carbon bond
• Saturated…


  Straight chains as there’s no double carbon to carbon bonds, high melting point
• Unsaturated…


  Have a double carbon to carbon bond, means they bend, low melting point
• Monounsaturated Fatty Acids…


  Are in warm blooded animals, at room temp they’re solids. E.g butter, lard
• Polyunsaturated Fatty Acids…


  Found in cold blooded animals, liquid at room temp. E.g. fish oil, vegetable oils
• Triglycerides Characteristics 


  • Low mass to energy ratio makes it a good energy store
  • Storing them doesn’t effect water potential as they’re insoluble
  • High hydrogen to oxygen ratio, makes them a good water source
  • Good insulation and protection in fatty tissue, found under skin or over organs