Lipids

• Made of: C, H, O (small proportion of O)

  Important for:

  • energy storage
  • structural component of membranes
  • thermal insulator
  • helps aquatic animals remain buoyant
• Glycerol

  • has 3 carbons
  • 3 hydroxil -OH groups

  H

  H-C-OH

  H-C-OH

  H-C-OH

  H
• Fatty acid

  • has a carboxylic acid group (-COOH)
  • with a long hydrocarbon chain which is hydrophobic and non-polar
• saturated fatty acids: no double bonds in hydrocarbon chain

  unsaturated fatty acids: contains one or more double bonds (C=C), lesser C-H bonds, lower melting point, liquid at room temp.
• Triglycerides

  • 3 fatty acids + 1 glycerol
  • linked by ester bonds
  • formed through condensation reactions
  • insoluble in water
  • soluble in organic solvents
• Phospholipids

  • 1 glycerol
  • 2 fatty acids
  • 1 phosphate group
  • has a hydrophilic head (phosphate group) that forms H bonds with water
  • hydrophobic tails that repels water

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