I did this as a lab in my biology class.

The project is to test the presence of the enzyme catalase(which is found in most living things) in a potato, and see if it reacts in other conditions. Catalase reacts with H2O2(hydrogen peroxide) and breaks it down into something else(H2 and O2 i think, i missed a test question because i couldnt remember what it broke down into). If you didnt have catalase in your body then hydrogen peroxide would kill your cells.

So, heres some supplies:

1. potato

2. knife or potato peeler

3. Hydrogen peroxide

4. clear plastic cup

5. Bunsen burner(i doubt you have this at your house but you could also use a stove i guess.

6. small glass cup or jar

Steps:

1. Peel the potato and try to shave it into thin slices(as thin as you can get them,)

2. Put the potato shavings into a plastic cup(fill the cup up about 1/5 of the way)

3. Pour hydrogen peroxide into the cup(past the shavings).

4. Swirl the cup around a bit and observe:

The hydrogen peroxide should start to foam which means that there is catalase present.

5. clean up and start over…

6. From here we did some thing where we got potato juice and used that but i think you might be able to use shavings again…. Get some more potato shavings.

7. put them in some water and boil the shavings really well(in a glass cup using either the bunsen burner or stove).

8. Put them in a plastic cup

9. pour hydrogen peroxide on them again.

10. This time it will not foam because the catalase should have rearranged itself physically.

Enzymes are proteins and they have a certain shape or folds, the catalase in the potato changes its shape when it is boiled so it will not react with hydrogen peroxide.