Digestive System

• What begins the digestion of starch in the mouth?

  Enzymes in saliva
• What is the role of hydrochloric acid in the stomach?

  It helps enzymes to digest proteins
• What is the function of the pancreas in digestion?

  It releases chemicals into the small intestine
• What does the liver produce that is stored in the gall bladder?

  Bile
• What is the function of the large intestine in digestion?

  It absorbs water from undigested food to produce faeces
• What are enzymes?

  • Biological catalysts
  • Speed up the rate of chemical reactions
• What is the lock and key theory in enzyme action?

  • The substrate's shape is complementary to the active site's shape
  • Forms an enzyme substrate complex when they bond
• How does temperature affect enzyme activity?

  As temperature increases, enzyme activity increases until the optimum temperature
• What is the optimum temperature for enzyme activity?

  37 °C
• What happens to an enzyme when the temperature becomes too hot?

  The active site changes shape, and the enzyme is denatured
• What is the optimum pH for most enzymes?

  7
• What occurs to the enzyme's active site if the pH is too acidic or too alkaline?

  The active site denatures
• What is amylase and its function?

  • Amylase is a carbohydrase
  • Breaks down starch to simple sugars
  • Made in salivary glands, pancreas, and small intestine
• What is the function of protease?

  • Helps break down proteins into amino acids
  • Made in pancreas, stomach, and small intestine
• What does lipase do?

  • Converts lipids into fatty acids and glycerol
  • Made in pancreas and small intestine
• What is the role of bile in digestion?

  • Made in the liver and stored in the gall bladder
  • Alkaline to neutralize hydrochloric acid from the stomach
  • Emulsifies fats to increase surface area for digestion
• How does increasing surface area affect fat digestion?

  It makes fats easier to digest