1. REVIEW

2. Catalysts produced by living things Bring about the chemical reactions in : Respiration to release energy from the breakdown of glucose in every plant and animal cell Digestion to break down large molecules into smaller ones Amylase, Protease, lipase, bile

3.  Protease and lipase enzymes are used in  Biological Washing powders to digest food stains  These washing powders work at lower temperatures so save money

4.  These enzymes convert glucose to fructose.  Fructose is much sweeter than glucose so less is needed in foods so they are less fattening so often used in slimming foods

5.  E.g., Amylase changes starch to sugars, maltose, glucose and dextrins  Amylase is produced - in the salivary glands  - in the pancreas  - in the small intestine

6.  Proteases convert proteins into amino acids  Proteases are produced in  - the stomach (pepsin)  - the pancreas  - the small intestine

7.  Convert fat into Glycerol and fatty acids  Lipase is produced in  - the pancreas  - the small intestine

8.  Bile is produced in the liver  It is stored in the Gall Bladder  Acidity in the stomach makes the pH too acidic in the small intestine for enzymes to work  Bile neutralises the acid and makes conditions in the small intestine alkaline  Bile emulsifies fats into tiny droplets.

9.  speed up reactions at low temperatures and normal pressures- very useful as many processes would need high temperatures and high pressures to run fast enough without the enzymes  Some enzymes slow down chemical processes in metabolism - INHIBITORS