Lesson Starter 1 What is a catalyst 2

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Lesson Starter 1. What is a catalyst? 2. What effect do catalysts have on

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?

Enzymes

Enzymes

Inside our bodies • 64, 000 red blood cells on the head of a

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.

Biological Catalysts • Biological catalysts ensure that the reactions are happening fast enough to

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

Hydrogen Peroxide • What does hydrogen peroxide break down into? • What chemical test

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

Experiment • Living things contain Enzymes • We can prove this through a simple

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

Apparatus • Test tube rack • 4 test tubes • Bunsen burner • Wooden

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

Experiment 1. Light the Bunsen burner and leave it on Fresh the safety flame

Experiment 1. Light the Bunsen burner and leave it on Fresh the safety flame liver 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 Cooked Fresh potato liver Hydrogen peroxide Cooked potato

Results Test Tube A- fresh liver B- cooked liver C- fresh potato D- cooked

Results Test Tube A- fresh liver B- cooked liver C- fresh potato D- cooked potato Oxygen produced? Catalyst Present?

Conclusion • Which tissues did you see bubbles being produced with? • What do

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

Conclusion • Hydrogen peroxide broke down into water and oxygen when fresh liver and

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

What enzyme? • Liver cells have a high concentration of the enzyme CATALASE •

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)