Cards (34)

  • What are the most abundant fats in the diet?
    Neutral fats, also known as triglycerides
  • What is the composition of a triglyceride molecule?
    A glycerol nucleus and three fatty acids
  • What type of food contains major amounts of neutral fat?
    Food of animal origin
  • What are phospholipids and cholesterol considered in the diet?
    They can be considered fats
  • What is cholesterol classified as?
    A sterol compound
  • How is cholesterol metabolized in relation to fats?
    It is metabolized similarly to fats
  • Where does the digestion of fats mainly occur?
    In the small intestine
  • What enzyme begins the digestion of triglycerides in the stomach?
    Lingual lipase
  • What is the significance of the amount of triglycerides digested in the stomach?
    It is less than 10 percent and unimpressive
  • What is the first step in fat digestion?
    Emulsification by bile acids and lecithin
  • What is emulsification in fat digestion?
    Breaking fat globules into smaller sizes
  • Where does most emulsification occur?
    In the duodenum
  • What does bile contain that is important for emulsification?
    Bile salts and phospholipid lecithin
  • How do bile salts and lecithin aid in emulsification?
    They decrease interfacial tension of fat
  • What happens to the interfacial tension of fat globules during emulsification?
    It decreases, making them easier to break
  • What is the average diameter of fat particles after emulsification?
    Less than 1 micrometer
  • How much does emulsification increase the total surface area of fats?
    By as much as 1000-fold
  • What is the role of lipase enzymes in fat digestion?
    They attack fat globules on their surfaces
  • What is the most important enzyme for triglyceride digestion?
    Pancreatic lipase
  • How quickly can pancreatic lipase digest triglycerides?
    Within 1 minute
  • What are the end products of triglyceride digestion?
    Free fatty acids and 2-monoglycerides
  • What role do bile salts play in fat digestion?
    They remove end products to prevent blockage
  • What do bile salts form to aid in fat digestion?
    Micelles
  • What is the size range of micelles formed by bile salts?
    3 to 6 nanometers in diameter
  • How do bile salts contribute to the absorption of fat digestates?
    They transport them to intestinal epithelial cells
  • What happens to bile salts after they ferry fat digestates?
    They are released back into the chyme
  • What form is most dietary cholesterol found in?
    Cholesterol esters
  • What enzymes hydrolyze cholesterol esters and phospholipids?
    Cholesterol ester hydrolase and phospholipase A2
  • How do bile salt micelles assist in cholesterol absorption?
    They ferry free cholesterol to intestinal cells
  • What are the steps involved in the digestion of fats?
    1. Emulsification by bile acids and lecithin
    2. Digestion by pancreatic lipase
    3. Formation of micelles for absorption
  • What are the roles of bile salts in fat digestion?
    • Emulsification of fat globules
    • Formation of micelles for transport
    • Removal of end products to prevent blockage
  • What are the types of fats present in the diet?
    • Neutral fats (triglycerides)
    • Phospholipids
    • Cholesterol and cholesterol esters
  • What are the end products of triglyceride digestion?
    • Free fatty acids
    • 2-monoglycerides
  • What enzymes are involved in the digestion of cholesterol esters and phospholipids?
    • Cholesterol ester hydrolase
    • Phospholipase A2