Digestive Enzymes

• Enzymes are catalysts produced by living things that speed up chemical reactions.
• Enzymes can only work till a certain temperature which they then get denatured
• Enzymes have special shapes so they can catalyse reactions
• Every enzyme has an active site with a unique shape that fits onto the substance involved
• Enzymes only catalyse one reaction (most of the time)
• If the substrate doesn't match the active site, the reaction won't be catalysed
• Enzymes have a lock and key system
• Enzymes need the right temperature or pH
• The reason why denaturing happens is due to the bonds holding the enzyme together break, changing the shape of the active site
• Pepsin has an optimum pH of 2 (To work in the stomach) unlike most other enzymes in the body which is around 7
• Inhibitors stop enzymes from working by binding to them so that they cannot react with their substrates
• Amylase is an example of a carbohydrase, which breaks down starch into glucose
• Amylase in made in the

  Salivary Glands

  Pancreas

  Small Intestine
• Proteases convert proteins into amino acids
• Protease is made in

  Stomach

  Pancreas

  Small Intestine
• Lipases break down lipids into fatty acids and glycerol
• Lipase is made in

  Pancreas

  Small Intestine
• Bile is produced in the liver and stored in the gall bladder before being released into the small intestine
• The Hydrochloric acid in the stomach makes the pH too acidic for enzymes in the small intestine, bile neutralises the acidity and makes the conditions alkaline
• Bile emulsifies fats, giving a much larger surface area for the enzyme lipase to work on, making digestion faster