Enzymes (principles of organisation)

• cell, tissue, organ, organ system
• What do salivary glands produce?


  Saliva
• What happens in the mouth?

  Physical and chemical digestion
• What does the liver produce?


  Bile
• Where is bile stored?

  Gall bladder
• What happens in the stomach?

  Physical and chemical digestion - contains enzymes (for food) and hydrochloric acid for microbes
• What does the pancreas do?


  Produce insulin
• What does the large intestine do ?


  Re absorb water and takes part in the formation feces
• What does the small intestine do ?


  Chemical digestion and absorption takes place here
• What is physical digestion?


  Mechanical breakdown of large pieces of food into smaller pieces e.g chewing in the mouth or churning in the stomach
• What is chemical digestion?


  Breakdown of small pieces of food into small, soluble molecules by chemicals called enzymes
• Enzymes are biological catalysts because they speed up the rate of chemical reactions inside the body
• The most important part of the enzyme is the active site, this allows the enzyme to join with the substrate that has a complementary shape. This is called the lock and key theory.
• At high temperatures enzymes denature. This means the shape of the active site changes. This means the enzyme can no longer fit together with molecule properly and does not work effectively.
• What is the optimum temperature for enzymes in the body?


  37 degrees
• The optimum pH for enzymes is 7 yet for the enzymes in the stomach it is 2
• How do you test for starch?


  Add iodine solution which changes from brown to blue-black
• How do you test for glucose?


  Add benedict's solution and heat which changes from blue to orange-red
• How do you test for protein?


  Shake with biuret solution which changes from pale blue to lilac
• The test for glucose is important because it can be used to show that starch is broken down into glucose by an enzyme called amylase. Amylase is a type of carbohydrase
• Carbohydrates, proteins and fats are all large molecules, which means they must be chemically digested so they can be absorbed into the blood and small intestine
• What does carbohydrase break carbohydrates into ?


  Sugars
• What does protease break proteins into?


  Amino acids
• What does lipase break lipids into ?


  Glycerol and fatty acids
• Where is carbohydrase made?


  small intestine, pancreas and salivary glands
• Where does carbohydrase work?


  small intestine and mouth
• Where is protease made?


  Small intestine, pancreas and stomach
• Where does protease work?


  small intestine and stomach
• Where is lipase made?


  small intestine and pancreas
• Where does lipase work?


  Small intestine
• Bile is made in the liver then stored in the gall bladder until it is released into the small intestine
• Bile

  neutralises the pH in the small intestine which creates the optimum pH for enzymes to work and prevents corrosion of the small intestine

  emulsifies fats which break down larger pieces into smaller pieces that have a larger surface area