1. Lesson Starter 1.What is a catalyst? 2.What effect do catalysts have on the input energy required for a reaction to happen? 3.What is special about a catalyst that makes it very useful?

2. Enzymes

3. Inside our bodies 64,000 red blood cells on the head of a pin All cells in our body carry out millions of chemical reactions total number of chemical reactions in the human body is about 400 billion per second every second of your life.

4. Biological Catalysts Biological catalysts ensure that the reactions are happening fast enough to keep us alive Biological catalysts are called ENZYMES Enzymes speed up the rate of BIOCHEMICAL reactions

5. Hydrogen Peroxide What does hydrogen peroxide break down into? What chemical test can we carry out to prove the hydrogen peroxide is broken down?

6. Experiment Living things contain Enzymes We can prove this through a simple experiment involving the decomposition of hydrogen peroxide

7. Apparatus Test tube rack 4 test tubes Bunsen burner Wooden splint Hydrogen peroxide Fresh liver Cooked liver Fresh potato Cooked potato

8. Experiment 1.Light the Bunsen burner and leave it on the safety flame 2.Add a small volume of hydrogen peroxide into each test tube 3.Add the fresh potato into the test tube and watch for bubbles 4.Test for oxygen using a glowing splint 5.Record your results 6.Repeat (3-5) for the cooked potato, the fresh liver and the cooked liver Hydrogen peroxide Fresh liver Cooked liver Cooked potato Fresh potato

9. Results Test TubeOxygen produced? Catalyst Present? A- fresh liver B- cooked liver C- fresh potato D- cooked potato

10. Conclusion Which tissues did you see bubbles being produced with? What do those tissues contain? Which tissue produced more bubbles?

11. Conclusion Hydrogen peroxide broke down into water and oxygen when fresh liver and fresh potato was used Fresh potato and liver contain enzymes Liver cells produced more bubbles

12. What enzyme? Liver cells have a high concentration of the enzyme CATALASE Catalase is an enzyme that speeds up the decomposition of hydrogen peroxide Potato cells also contain catalase (but not as high a concentration)