Extra: In this activity you explored fruits that contain proteases, but many fruits do not contain proteases.

What do your results tell you about how the proteases affect the gelatin solidification process and how heat affects the proteases?.

(This will probably take about four hours.) In which condition(s) does the gelatin set? In which condition(s) does the gelatin remain a liquid? Are there any in-between cases? Continue checking their consistency once an hour until the gelatin in the cup without fruit solidifies.

An hour after you put the cups in the refrigerator, check the consistency of the gelatin in each cup.

Refrigerate all three cups, noting the time at which you put them inside the refrigerator.

Use a different, clean utensil to stir each cup.

Thoroughly stir the contents of each cup.

You should now have three cups with gelatin liquid in them.

Add one cup of gelatin liquid to each of the cups with fruit, and add the third cup portion to an empty cup.

You will want to prepare at least three cups of liquid gelatin.

Make the gelatin dessert according to the package instructions.

If it's difficult to tell the difference between the raw and cooked fruit by looking at them, you may want to label the cups (with tape and a permanent marker or pen).

Add the raw fruit to one plastic cup or drinking glass and the cooked fruit to a different plastic cup.

Do this by either steaming or boiling the fruit (with about one quarter cup of water) for five minutes.

Carefully cut up one cup of the fresh fruit.

You may want to have an adult help cut up the fruit and use the stove.

Three utensils for stirring, such as spoons or forks.

Gelatin mix (such as JELL-O), enough to make three cups of gelatin.

Tape and permanent marker or pen (optional).

Three plastic cups or drinking glasses, each at least 12 ounces in size.

Pot, large enough to hold three cups of liquid.

One cup of one of the following types of fruit, which should contain proteases: figs, ginger root, guava, kiwi fruit, mango, papaya or pineapple.

To do this you'll inactivate these proteases by using heat. In this activity you'll explore whether these protease enzymes are preventing the gelatin from solidifying (by cutting the gelatin's collagen proteins into such small pieces that they are no longer able to tangle together and create a semisolid structure). Proteases specifically act like a pair of scissors, helping reactions take place that cut other proteins up.

Enzymes help make certain chemical reactions happen. The fruits listed above contain proteases, which are enzymes. This results in your wiggly-jiggly gelatin dessert. After the gelatin cools, the proteins remained tangled. Gelatin, which is a mixture of collagen proteins, solidifies when you cook it because its proteins form tangled mesh pockets that trap the water and other ingredients. Collagen is found in many parts of the body and helps give animals their structure, or shape.

Gelatin is made from collagen, which is a structural protein found in all animals. People have a hard time getting the gelatin to solidify when they add these fruits.

If you like making gelatin for dessert, the box often recommends not adding certain kinds of fruit, including pineapple, kiwi, mango, ginger root, papaya, figs or guava. In this activity you'll get to determine if certain enzymes in some fruits can keep the gelatin from gelling-and whether there's a way to still include these fruits without ruining your gelatin dessert! Have you ever noticed that if you're making a gelatin dessert, such as JELL-O, it's not recommended to use certain fruits, like pineapple? Why is this? These fruits may prevent the gelatin from solidifying.

Jello gelatin