Digestion and absorption

• What is the role of amylase in digestion?

  Carbohydrate digestion
• Where is amylase produced?

  Mouth and pancreas
• What does maltase do in digestion?

  Digests starch into maltose
• Where is maltase located?

  Lining of the ileum
• What is the function of sucrase?

  Hydrolyzes sucrose
• What does lactase hydrolyze?

  Lactose
• What type of digestion do lipases assist with?

  Lipid digestion
• Where are lipases produced?

  Pancreas
• What are the two types of protease enzymes and their functions?

  • Endopeptidases: Hydrolyze peptide bonds in the central region of proteins.
  • Exopeptidases: Hydrolyze peptide bonds at the terminal amino acids.
• What do dipeptidases do?

  Hydrolyze bonds between two amino acids
• Where are dipeptidases located?

  Cell surface membrane of ileum epithelial cells
• What is the role of bile salts in lipid digestion?

  • Assist lipase in lipid digestion
  • Emulsify fats into smaller droplets
  • Increase surface area for lipase action
• Where is bile produced and stored?

  Produced in liver, stored in gallbladder
• What is the purpose of emulsification in digestion?

  To break fat droplets into smaller droplets
• What happens to triglycerides before digestion?

  They need to be emulsified
• Where does lipid digestion occur?

  Small intestine
• What is the main form of lipid storage in humans?

  Triglycerides
• What does Dinitrophenol (DNP) prevent in cells?

  Respiratory chain from working
• Why does pump Y not work in the presence of DNP?

  Requires ATP, which is not produced
• Why are sodium ions and amino acids not absorbed in the presence of DNP?

  No concentration gradient for absorption
• What mechanism allows amino acids to leave the epithelial cell?

  Co-transport with facilitated diffusion
• What is actively transported out of epithelial cells into blood?

  Na⁺
• What does the active transport of Na⁺ create?

  A concentration gradient for sodium
• How do Na⁺ and glucose move into epithelial cells?

  By facilitated diffusion via co-transporter proteins
• What happens to glucose after it enters the epithelial cell?

  It diffuses out of the cell into the blood
• What type of diffusion does glucose use to exit the epithelial cell?

  Facilitated diffusion
• How does the transport of Na⁺ influence glucose transport into epithelial cells?

  The sodium gradient drives glucose uptake via co-transport