B2.2 enzymes and digestion

• enzymes are catalysts produced by living things
• a catalyst is a substance which increases the speed of reaction without being changes or used in the reaction
• Enzymes have special shapes so they can catalyse reactions
• Enzymes need the right temperature and pH


  Changing the temperature changes the rate of an enzym-catalysed reaction
• Digestive enzymes break down big molecules
• carbohydrates convert carbohydrates into simple sugars
• Amylase

  Starch —- ———>Maltose

  Enzyme
• Proteases convert proteins into amino acids
• Where are proteases made ?


  >the stomach

  >the pancreas

  >the small intestine
• Where is amylase made ?


  >the salivary glands

  >the pancreas

  >the small intestine
• what does amylase do?


  It’s an example of a carbohydrase, it breaks down starch
• Lipases convert lipids into glycerol and fatty acids
• Bile neutralises the stomach acids and emulsifies fats
• Salivary glands 


  Produce amylase enzymes in the saliva
• Stomach


  Produces the protease enzyme, pepsin
• Liver


  Where bile is produced
• Gall bladder


  Where bile is stored
• Large intestine


  Where excess water is absorbed from the food
• Pancreas


  Produces protease, amylase and lipase enzymes
• Small intestine


  Where digested food is absorbed
• Rectum


  Where faeces are stored before they are released
• How does temperature effect the functioning of enzymes?


  High temperatures start to break apart the bonds holding the enzymes togethee