Lipid digestion

• What are the key marking points in lipid digestion and absorption?

  • Role of lipase
  • Function of bile salts
  • Formation of micelles
  • Absorption process in the ileum
• What enzyme digests lipids?

  Lipase
• Where is lipase produced?

  In the pancreas
• Where does lipase act?

  In the duodenum and ileum
• What do bile salts do in lipid digestion?

  Emulsify lipids to form droplets
• What is the role of micelles in lipid absorption?

  They increase solubility and transport fatty acids
• What do micelles contain?

  Fatty acids, glycerol, monoglycerides, bile salts
• Why are fatty acids not water-soluble?

  They are non-polar
• How do micelles assist in lipid absorption?

  They carry fatty acids to epithelial cells
• How do fatty acids enter epithelial cells?

  By simple diffusion
• Why can fatty acids diffuse through cell membranes?

  They are lipid soluble and non-polar
• Where are triglycerides reassimilated in epithelial cells?

  In the smooth endoplasmic reticulum
• What is a chylomicron?

  A triglyceride combined with protein
• How are processed triglycerides released from epithelial cells?

  By exocytosis in vesicles
• What happens to triglycerides after they are released?

  They are absorbed by lacteals
• Where do triglycerides go after entering the lymphatic system?

  They reach a blood vessel near the vena cava
• What are the key marking points for a long answer question on lipid absorption?

  1. Define micelles
  2. Role of micelles in absorption
  3. Mechanism of simple diffusion
  4. Formation of triglycerides or chylomicrons
  5. Transport to the lymphatic system
• What are the advantages of smaller lipid droplets and micelles?

  • Smaller droplets increase surface area for lipase
  • Micelles transport fatty acids to epithelial cells
• How do the Golgi apparatus and endoplasmic reticulum contribute to lipid absorption?

  They modify triglycerides and package them
• What do Golgi apparatus combine with triglycerides?

  Proteins to form chylomicrons
• What is the process of releasing triglycerides from epithelial cells?

  They are packaged into vesicles and exocytosed
• What is the final step for triglycerides after being released?

  They are absorbed by lacteals
• What happens to triglycerides in the lymphatic system?

  They are transported to the bloodstream
• What are common exam questions related to lipid digestion and absorption?

  • Describe lipid absorption and transport
  • Importance of micelles in absorption
  • Advantages of smaller droplets and micelles
  • Role of Golgi apparatus and endoplasmic reticulum