How the Digestion System Works

• What is the primary function of digestion?

  To break down large, insoluble molecules into soluble substances
• How are smaller molecules absorbed into the blood?

  Through the wall of the small intestine
• What type of breakdown occurs in the mouth during digestion?

  Physical breakdown of food
• What do carbohydrases catalyse?

  The breakdown of carbohydrates to simple sugars
• What do proteases catalyse?

  The breakdown of proteins to amino acids
• What do lipases catalyse?

  The breakdown of lipids to fatty acids and glycerol
• What are the key enzymes involved in digestion and their reactions?

  • Amylase: starch → sugars
  • Protease: protein → amino acids
  • Lipase: lipids → fatty acids + glycerol
• Why is pH important in enzyme reactions?

  It affects the rate of reaction of enzymes like amylase
• Why is it important to know the optimal pH for enzymes?

  To ensure enzymes work effectively in the digestive system
• How do the functions of the mouth, stomach, small intestine, and large intestine differ in digestion?

  The mouth chews, the stomach churns, the small intestine absorbs, and the large intestine removes water
• What are digestive enzymes produced by?

  specialised cells in glands and in the lining of the small intestine
• Where are digestive enzymes passed out to?

  from the glands, into the cavity of the digestive system
• Where do digestive enzymes work?

  outside the cells - unlike most enzymes
• Why does the digestive system break down food into smaller pieces?

  to increase the surface area for enzymes to work on
• Why does the digestive system contain muscles?

  to move the food along
• Is the mouth alkaline or acidic?

  alkaline
• Is the small intestine alkaline or acidic?

  Alkaline
• Is the stomach alkaline or acidic?

  Acidic
• What is each type of food digested by?

  a specific enzyme
• Where are amylase produced?

  the salivary glands, pancreas & the small intestine
• Where are proteases produced?

  the stomach, pancreas & the small intestine
• Where are lipase produced?

  the pancreas & the small intestine