trig;ycerides

• What is one major function of lipids in the human diet?

  They are a major source of energy
• Name two sources of lipids.

  Olive oil and butter
• How do lipids function in energy storage?

  They are stored in adipose tissue
• What role does adipose tissue play in the body?

  It insulates the body and stores energy
• How do lipids provide waterproofing?

  Oils coat feathers of aquatic birds
• What are the two main categories of lipids?

  Triglycerides and phospholipids
• What is the general structure of a triglyceride?

  One glycerol bonded to three fatty acids
• What are the two key parts of a fatty acid molecule?

  Carboxylic group and carbon chain
• What characterizes a saturated fatty acid?

  Only single covalent bonds between carbons
• What is an unsaturated fatty acid?

  It has at least one double bond between carbons
• What is a monounsaturated fatty acid?

  One double bond in the carbon chain
• What is a polyunsaturated fatty acid?

  Two or more double bonds in the carbon chain
• How are triglycerides formed?

  From one glycerol and three fatty acids
• What is the structure of a glycerol molecule?

  It has three hydroxyl groups
• What type of bond forms between glycerol and fatty acids?

  An ester bond
• What is esterification?

  The process of forming an ester bond
• What is produced during the formation of triglycerides?

  A molecule of water
• What reaction breaks down triglycerides in the digestive system?

  Hydrolysis reaction
• What do lipase enzymes do in digestion?

  They break the ester bonds
• Why are triglycerides considered hydrophobic?

  They are non-polar molecules
• What does the large number of carbon and hydrogen atoms in triglycerides allow?

  A great deal of energy to be released
• What are the functions of lipids in the human body?

  • Major source of energy
  • Energy storage in adipose tissue
  • Insulation to reduce heat loss
  • Protection of internal organs
  • Waterproofing for feathers of aquatic birds
  • Structural components of membranes
• What is the difference between saturated and unsaturated fatty acids?

  • Saturated fatty acids: only single covalent bonds
  • Unsaturated fatty acids: at least one double covalent bond
• What is the process of triglyceride formation and breakdown?

  Formation:

  1. Glycerol + 3 fatty acids
  2. Ester bond formation (esterification)
  3. Water is produced

  
  

  Breakdown:

  1. Hydrolysis reaction
  2. Lipase enzymes break ester bonds
  3. Glycerol and fatty acids released
• What are the characteristics of triglycerides?

  • Non-polar and hydrophobic
  • High energy release due to carbon and hydrogen content