lipids

• What are the two main types of lipids?

  Triglycerides and phospholipids
• What is the structure of glycerol?

  It contains 3 hydroxyl groups
• What do triglycerides and phospholipids contain?

  They contain glycerol and fatty acids
• What is the characteristic of fatty acids?

  They are long chains of hydrocarbons
• What group is found at one end of fatty acids?

  A carboxyl group
• What are the two types of fatty acids?

  Saturated and unsaturated
• What do unsaturated fatty acids contain?

  Carbon-carbon double bonds
• How many fatty acids are in a triglyceride?

  Three fatty acids
• What are triglycerides typically found as?

  Fats and oils
• What type of bond holds all lipids together?

  Ester bonds
• What is the nature of triglycerides in water?

  They are insoluble in water
• Why are triglycerides beneficial for cells?

  They won't decrease the water potential
• How are triglycerides soluble in ethanol?

  They dissolve in ethanol
• What is the structure of a phospholipid?

  One glycerol, two fatty acids, one phosphate group
• What do phospholipids have in terms of polarity?

  A hydrophilic head and hydrophobic tails
• How do phospholipids orient themselves in water?

  Tails are away from the water
• What structure do phospholipids form in cells?

  Bilayers for membranes
• What is the food test for lipids called?

  The emulsion test
• What is the first step in the emulsion test?

  Add ethanol to the sample
• What happens after adding ethanol in the emulsion test?

  Shake to dissolve lipids
• What indicates the presence of lipids in the emulsion test?

  A white emulsion will form
• What are the learning outcomes related to lipids?

  • Describe the difference between saturated and unsaturated fatty acids
  • Describe and compare the structures of triglycerides and phospholipids
  • Explain how the structures of lipids relate to their functions
  • Describe the biochemical test for lipids
• Compare the structures of triglycerides and phospholipids.

  • Both contain glycerol
  • Both are held together by ester bonds
  • Triglycerides have 3 fatty acids; phospholipids have 2 fatty acids and a phosphate group