lipids

• 2 types of lipids:

  triglycerides & phospholipids
• triglycerides

  condensation reaction of 1 glycerol and 3 fatty acids removing 3 molecules of water forming ester bonds
• properties of triglycerides

  energy storage: large ratio of C-H bonds

  metabolic water source: high ratio of H : O

  insoluble: fatty acids = hydrophobic so can’t affect water potential & osmosis

  relatively low in mass: can store a lot of lipids
• phospholipids

  1 phosphate group and a glycerol and 2 fatty acids
• properties of phospholipids

  forms a bilayer

  phosphate group: hydrophilic

  • attracts water

  fatty acids: hydrophobic

  • repels water
• how is an ester bond formed

  through the condensation reaction between a glycerol and fatty acid
• saturated fatty acids

  single bonds between carbon in the hydrocarbon chain
• unsaturated fatty acids

  at least 1 double bond between carbons in the hydrocarbon chain
• test for lipids

  • dissolve sample in ethanol & shake
  • add distilled water

  positive result: white emulsion