Topic 2 ORGANISATION PMT

• Organs in the digestive system

  • Glands (salivary glands, pancreas)
  • Stomach
  • Small intestine
  • Liver
  • Gall bladder
  • Large intestine
  • Rectum
  • Anus
• Enzymes

  Biological catalysts that increase the rate of reaction without being used up
• Enzymes

  • They can both break up large molecules and join small ones
  • They are protein molecules and the shape of the enzyme is vital to its function
  • Each enzyme has its own uniquely shaped active site where the substrate binds
• Lock and Key Hypothesis

  1. Substrate shape is complementary to active site shape, forming enzyme-substrate complex

  2. Reaction takes place and products are released
• Optimum temperaturefor enzymes in the body?

  Around 37 degrees Celsius (body temperature), rate increases up to this then rapidly decreases
• Denaturation


  When bonds in enzyme structure break due to extreme temperature or pH, changing the shape of the active site so substrate can no longer fit
• Types of enzymes


  • Carbohydrases (break down carbohydrates into simple sugars)
  • Proteases (break down proteins into amino acids)
  • Lipases (break down lipids into fatty acids and glycerol)
• Heartbeat process


  Blood flows into atria, atria contract to force blood into ventricles, ventricles contract to pump blood out
• Causal mechanism


  An explanation of how one factor influences another
• How is rate of blood flow calculated ?

  Rate of blood flow = Volume of blood / Number of minutes