digestion and absorption

• What does digestion involve?

  Hydrolysis of large insoluble molecules
• What are the three main types of molecules involved in digestion?

  Carbohydrates, lipids, and proteins
• What are the two enzymes mentioned for carbohydrate digestion?

  Amylase and membrane-bound disaccharidases
• Where is amylase produced?

  In the pancreas and salivary glands
• Where does carbohydrate digestion begin?

  In the mouth
• What happens to starch during carbohydrate digestion?

  It is hydrolyzed into disaccharides
• What is the role of membrane-bound disaccharidases?

  To hydrolyze disaccharides into monosaccharides
• What are the three types of enzymes that digest proteins?

  Endopeptidases, exopeptidases, and dipeptidases
• Where does protein digestion start?

  In the stomach
• What is the function of lipase in lipid digestion?

  To hydrolyze ester bonds in triglycerides
• Where is lipase produced?

  In the pancreas
• What is the role of bile salts in lipid digestion?

  To emulsify lipids into smaller droplets
• How does emulsification benefit lipid digestion?

  It increases surface area for faster hydrolysis
• What is a micelle?

  A sphere made of fatty acids and monoglycerides
• How do fatty acids and monoglycerides enter epithelial cells?

  By diffusion through the plasma membrane
• What happens to fatty acids inside epithelial cells?

  They are reformed into triglycerides
• What is a chylomicron?

  A triglyceride combined with a protein
• How are chylomicrons absorbed into the body?

  Through lacteals in the lymphatic system
• What is the role of villi in the ileum?

  To increase surface area for absorption
• How do microvilli enhance absorption in the ileum?

  By further increasing surface area
• What is co-transport in nutrient absorption?

  A type of active transport for glucose and amino acids
• What is the primary function of the ileum?

  To absorb digested food molecules
• How do monosaccharides and amino acids get absorbed?

  By co-transport and facilitated diffusion
• What is the main role of the capillary network in the villi?

  To maintain concentration gradient for absorption
• Why is a short diffusion distance important in absorption?

  It allows for rapid nutrient uptake
• How does the structure of the ileum facilitate absorption?

  Villi and microvilli increase surface area
• What happens to lipids after they are absorbed into epithelial cells?

  They are reassembled into triglycerides
• What is the final destination of chylomicrons in the body?

  They enter the lymphatic system
• How do lipids travel after being packaged into chylomicrons?

  Through lacteals to the lymphatic system
• What is the significance of the lymphatic system in lipid absorption?

  It transports lipids to the bloodstream
• What is the overall process of digestion and absorption?

  Breaking down food and absorbing nutrients