Lipids

• What are the two types of lipids you need to know?

  • Triglycerides
  • Phospholipids
• What is the structure of a triglyceride?

  One glycerol molecule and three fatty acid chains
• How are triglycerides formed?

  Through three condensation reactions forming ester bonds
• What is the difference between saturated and unsaturated fatty acids?

  Saturated fatty acids have no double bonds, while unsaturated have at least one double bond
• What is the function of triglycerides?

  They serve as an energy store
• Why do triglycerides not affect water potential?

  Because they are large and hydrophobic
• What is the structure of phospholipids?

  One glycerol, two fatty acid chains, and one phosphate group
• What property does the phosphate group give to phospholipids?

  A negative charge that attracts water
• What is the unique property of the phospholipid bilayer?

  Hydrophilic heads face outward and hydrophobic tails face inward
• How do you test for lipids?

  Dissolve the sample in ethanol, shake, then add distilled water; a positive result shows a white emulsion.