To investigates the enzymatic effect of various materials in the hydrogen peroxide solution. Apparatus & Equipment:
Beaker Test tubes
Either: water bath (95oC) or Bunsen burner Materials:
Fresh Liver Potato cubes
Manganese dioxide Hydrogen peroxide**
Wood splints **Caution: Hydrogen peroxide is formed continuously as a by-product of chemical reactions in living cells; it is a very toxic (poisonous) substance.
[Note: using boiling tubes may provide better results.] 1. Label six fresh empty test or boiling tubes 1, 2, 3, 4, 5, 6 and stand them in a rack. 2. Using a razor blade, cut the provided liver into several pieces of roughly 0.8 cm x 0.8 cm x 0.5 cm. 3. Place one piece of liver into tube 1. 4. Boil 100 cm3 of water in a beaker. (If you’re using a water bath set at 95oC, this step is not necessary). 5. Place the second piece of liver into the bottom of tube 2. Using a wooden splint, gently spread the liver, without mashing it, over as wide an area as possible of the bottom of the test or boiling tube. Place tube 2 in the boiling or water bath (95oC) for about five minutes. 6. Using the weighing balance, measure out two 0.5 g portions of manganese dioxide powder each onto a weighing boat. Pour each portion into tube 5 and tube 6.
7. Put tube 6 in the beaker of boiling water or water bath (95oC) for five minutes. 8. After five minutes let cool tube 2 and 6. 9. *Now put the third piece of liver into test or boiling tube 3. With the wooden stick provided, mash it gently into a pulp. 10. Now put the third piece of liver onto a white tile. With a mortar and pestle, mash it gently into a pulp. Scoop the pulp into tube 3. 11. Cut potato cubes of roughly 0.8 cm x 0.8 cm x 0.5 cm. Place one cube into a tube 4. 12. Prepare another six fresh empty test or boiling tubes and stand them in a rack. Put 5 cm3 of hydrogen peroxide into each of them.