JELL-O Enzyme Lab

I highly recommend this lab. It is a great way for students to make the connection between enzymes and their role in digestion. Students will also explore the impact temperature can have on enzymes. The action of an enzyme will be tested in this lab using three different pineapple samples and gelatin.

I cannot stress enough how important it is to include labs/experiments for each unit in science. Students get the opportunity to apply science concepts learned in class to a hands-on activity, which most students really enjoy. It also strengthens social building skills as they work together in groups with their classmates. Okay, so let’s talk about this lab!

Have you ever seen the warning on the back of a JELL-O box that says not to use fresh pineapples with it? Most people, both kids and adults, don’t know that fresh pineapples have an enzyme called bromelain in them that can interact with your JELL-O dessert. You can put fresh pineapples in gelatin; it just won't become a jiggly solid. It will remain a liquid. It won't set.

The enzyme bromelain, in its fresh form, breaks down protein, and JELL-O contains gelatin, which is a collagen/protein. This is why if bromelain comes in contact with the gelatin, it will cause the gelatin to remain soupy rather than solidifying into a jiggly solid, even when placed in the refrigerator for hours.

Canned pineapple, on the other hand, can be added to a gelatin dessert because it has been heated during the canning process. The heat denatures the enzyme bromelain, so that it can't function, which means it won't break down the gelatin. The gelatin will solidify and become a jiggly, solid dessert when placed in the fridge if using canned pineapple.

In this experiment students will test fresh and canned pineapples in gelatin then record and analyze the results of each sample as time passes. You will have to leave the results overnight in the fridge at the teacher's lounge, so students can see how the results, as it takes 2-4 hours for the gelatin to solidify when kept cold.

If incorporating this lab with the digestive system unit, teach students about the main digestive enzymes in the body-amylase, pepsin, and lipase and how they help chemically break down, or digest food. This is also a good experiment to do after teaching students the different ways enzymes are denatured, one being heat. Knowing the ways an enzyme can be denatured will help students understand the results of the gelatin with the canned pineapple and fresh pineapple gelatin cups. Having all this information beforehand will help them better understand the results of the experiment.

Materials:

1.Styrofoam or glass beakers (Three cups per lab group)

2.Jell-O (or another brand of gelatin dessert)

3.Fresh Pineapples cut in small cubes

4.Canned Sliced or Cubed Pineapples (Drain the juice, as too much juice will water down

the gelatin causing it not to set properly).

5.Masking Tape (for labeling which type of pineapple is in each container)

Procedure:

1.Prepare the gelatin dessert as instructed on the box- mixing the gelatin with hot water.

2.Stir the mixture well and then pour it into equal amounts into the two beakers or cups.

3.With tape, label each cup. One will be labeled, "Fresh Pineapples", one will be labeled,

"Canned Pineapple", and the last one will be labeled, "No Pineapples".

4.Make sure to cut the pineapples into equal sizes before placing them into the two

cups.

5.Make sure to put the fresh and canned pineapples into the right cups or beakers.

6.Now let the three cups of gelatin set by placing them in the refrigerator for 2-4 hours.

7.Remove the three labeled gelatin cups from the refrigerator.

8.Students will observe the results and record their observations in their science

journals.