Lipids

• Properties of lipids


  Insoluble in water, but soluble in organic solvents such as alcohols and acetone.

  Produce fats and are solid/liquid at room temp
• What are lipids made from?


  carbon, hydrogen, oxygen
• What are the two groups of lipids?

  triglycerides and phospholipids
• Properties of triglycerides


  Insoluble in water

  Hydrophobic

  Rich in energy - often used in energy stores

  They can be hydrolysed and used as respiratory substrate to generate ATP
• How are triglycerides formed?


  Each fatty acid is joined and combined with the glycerol forming an ester bond in three condensation reactions.
• where are lipids stored?


  adipose tissue
• Roles of lipids


  heat insulation

  protection for organs

  energy storage molecule
• Glycerol formula


  C3H8O3

  
• Saturated fatty acids


  no double bond between the carbon atoms (only single bonds between the carbons)

  
• Unsaturated fatty acids


  has at least one double bond between the carbon atoms

  
• Palmitic acid


  a 16 carbon saturated fatty acid - it has the maximum number of hydrogens

  
• Palmitoleic acid


  a 16 carbon unsaturated fatty acid - there is capacity to accept more hydrogen

  
• what does a phospholipid molecule consist of?


  a glycerol molecule with two fatty acids and phosphate group

  
• What is a phosphate group?


  a phosphorus atom bonded to four oxygen atoms
• what is cholesterol?


  a lipid that helps maintain the fluidity of cell membranes. It is used to make steroids such as oestrogen and testosterone
• What do phospholipids form?


  cell membranes
• What are the properties of phospholipids?


  hydrophilic head and hydrophobic tail

  polar - has 2 charged regions
• What do phospholipids form?


  A double layer, heads outside and tails inside, forming a barrier against water soluble substances (bilayer)