Lipids

• What are the two types of lipids discussed in the video?

  Triglycerides and phospholipids
• What is the structure of a glycerol molecule?

  It is a three carbon compound
• How many fatty acid chains does a triglyceride have?

  Three fatty acid chains
• What replaces the third fatty acid chain in a phospholipid?

  A phosphate group
• How are triglycerides formed?

  • Involves three condensation reactions
  • Glycerol bonds with three fatty acids
  • Three water molecules are produced
  • Three ester bonds are formed
• What type of reaction forms triglycerides?

  Condensation reactions
• What is an ester bond?

  A bond between carbon and oxygen
• What does the term "R group" refer to in fatty acids?

  Variable group of carbons and hydrogens
• What does saturated mean in terms of fatty acids?

  All carbons have single bonds
• What does unsaturated mean in terms of fatty acids?

  At least one double bond between carbons
• Why do triglycerides store a lot of energy?

  High ratio of carbon to hydrogen bonds
• How do triglycerides act as a metabolic water source?

  They form water when oxidized
• Why are triglycerides hydrophobic?

  They repel water and are insoluble
• What is a significant advantage of triglycerides being hydrophobic?

  They do not affect water potential
• How do triglycerides compare in mass to muscle tissue?

  They are relatively low in mass
• What is the emulsion test for lipids?

  1. Dissolve sample in ethanol
  2. Add distilled water and shake
  3. Positive result: white emulsion forms
  4. Emulsion means tiny droplets, not solid
• What is the structure of phospholipids?

  Two fatty acids and one phosphate group
• How are phospholipids formed?

  Through condensation reactions with glycerol
• What charge does the phosphate group in phospholipids have?

  A negative charge
• What is the hydrophilic head of a phospholipid?

  The part that attracts water
• What are the hydrophobic tails of phospholipids?

  The parts that repel water
• How do phospholipids arrange themselves in water?

  • Form a bilayer structure
  • Hydrophobic tails face inward
  • Hydrophilic heads face outward
  • Essential for cell membranes
• Why are phospholipids described as polar?

  They have charged regions
• What is the main function of triglycerides?

  Energy storage
• What is the main function of phospholipids?

  Form cell membranes
• What should you know about triglycerides and phospholipids for the exam?

  • Structure and formation
  • Types of bonds involved
  • Functions and properties
  • Testing methods (emulsion test)