Science Digestive System

• What is digestion?

  The breakdown of large molecules
• What is the purpose of emulsification in digestion?

  To increase surface area for lipase action
• What does the salivary gland produce and where does it help?

  • Produces: Saliva
  • Helps in: Mouth
• How does saliva aid in digestion?

  It contains amylase to break down starch
• What does the liver produce and where does it help?

  • Produces: Bile
  • Helps in: Small intestine
• What is the role of bile in digestion?

  Emulsifies fat and neutralizes acid
• What enzymes does the pancreas produce and where do they act?

  • Enzymes: Amylase, proteases, lipases
  • Acts in: Small intestine
• What is the function of amylase, proteases, and lipases?

  They break down food into smaller molecules
• What is the Biuret test used for?

  • Tests for: Protein
  • Negative result: No change (blue)
  • Positive result: Purple
• What is the iodine test used for?

  • Tests for: Starch
  • Negative result: No change (brown)
  • Positive result: Black
• What is the Benedict's test used for?

  • Tests for: Sugar
  • Negative result: No change (blue)
  • Positive result: Brick red
• What is the ethanol and water test used for?

  • Tests for: Fat
  • Negative result: No change
  • Positive result: White emulsion
• What are enzymes and their function in digestion?

  Proteins that speed up biochemical reactions
• What are the adaptations of the small intestine for absorption?

  • Villi increase surface area
  • Large blood supply for quick absorption
• What is the order of organs food passes through during digestion?

  1. Mouth
  2. Oesophagus
  3. Stomach
  4. Small intestine
  5. Large intestine
  6. Rectum
  7. Anus
• What is the job of the mouth in digestion?

  Mechanically and chemically digests food
• How does the oesophagus aid in digestion?

  It squeezes food down to the stomach
• What is the function of the stomach in digestion?

  Mechanically digests food and kills bacteria
• What does the small intestine do in digestion?

  Produces enzymes and absorbs simple molecules
• What is the role of the large intestine?

  Absorbs water from undigested food
• What do the rectum and anus do in digestion?

  Store and eliminate waste from the body