Biology B3 - organisation & digestion

• Enzymes

  • Biological catalysts 
  • Speed up reaction
  • Not used up
• Lock & Key model

  • Enzyme binds to substrate
  • At active site
  • Enzymesubstrate complex
  • Substrate converted to products
  • Product released from active site
  • Enzyme not used up
  • Active site specific to one substrate
• Food tests

  1. Sweet sugars - benedict's test

  • Benedict's solution 
  • Heat
  • Blue to orange

  2. Starch - iodine test

  • Idoine 
  • blue/black

  3. Protein - biuret's test

  • Biuret solution 
  • Blue to purple/lilac

  4. Lipid - emulsion test

  • Ethanol
  • Shake
  • Water
  • White emulsion
• Nutrients

  Carbohydrates - instant energy source - rice, potato, bread

  Protein - growth & repair - meat, nuts, beans

  Fat (lipid) - energy store/insulation/protects organs - butter, cheese, oils
• Mouth - Food group, Enzyme, Products

  Food group

  • carbohydrate

  Enzyme

  • carbohydrase
  • salivary amylase

  Products

  • simple sugars
• Stomach - Food group, Enzyme, Products

  Food group

  • protein

  Enzyme

  • protease

  Products

  • amino acids
• Liver - Food group, Enzyme, Products

  Food group

  • lipid (fat)

  Enzyme

  • bile (not an enzyme)

  Products

  • emulsifies fat
• Pancreas - Food group, Enzyme, Products

  Food group

  • carbohydrate
  • protein
  • lipids

  Enzyme

  • carbohydrase
  • protease
  • lipase

  Products

  • fatty acids & glycerol