triglycerides

• • Triglycerides have one molecule of glycerol with three fatty acids attached to it.
  • They're synthesised by the formation of an ester bond between each fatty acid and the glycerol molecule.

  A) Glycerol

  B) fatty acid

  
• • One triglyceride molecule has three ester bonds.
  • Each ester bond is formed by a condensation reaction (in which a water molecule is released).

  Triglycerides break down when the ester bonds are broken. Each ester bond is broken in a hydrolysis reaction
• what is the process in which triglycerides are synthesised called

  esterification.
• formation and breakdown of a triglyceride

  A) glycerol

  B) fatty acids

  C) hydrolysis

  D) ester bond

  E) triglyceride

  F) esterification

  
• • Fatty acid molecules have long 'tails' made of hydrocarbons (compounds that contain only carbon and hydrogencarbon atom links
  • The tails are 'hydrophobic' (they repel water molecules).
  • These tails make lipids insoluble inwater.
  • All fatty acids have the same basic structure, but the hydrocarbon tail varies

  
• Saturated fatty acids 


  don't have any double bonds between their carbon atoms in their hydrocarbon tails. The fatty acid is 'saturated' with hydrogen.

  
• Unsaturated fatty acids 


  have at least one double bond between carbon atoms, which causes the chain to kink.

  
• • In animals and plants, triglycerides are mainly used as energy storage molecules.
  • Some bacteria (e.g. Mycobacterium tuberculosis) use triglycerides to store both energy and carbon.
  • Triglycerides are good for storage because the long hydrocarbon tails of the fatty acids contain lots of chemical energy -a load of energy is released when they're broken down. Because of these tails, lipids contain about twice as much energy per gram as carbohydrates.
• Triglycerides are also insoluble, so they don't cause water to enter the cells by osmosis which would make them swell. The triglycerides bundle together as insoluble droplets in cells because the fatty acid tails are hydrophobic (water-repelling) - the tails face inwards, shielding themselves from water with their glycerol heads