Gelatin and Enzyme Lab PDF

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Gelatin and Enzyme Lab (Modified for Pineapple) Objectives: To test if gelatin contains proteins that enzymes can break down. To understand if the amount of the enzyme affects the breakdown of protein.

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Materials: gelatin (any flavour) 3 cups Pineapple spoon black marker to label cups

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Procedure: 1. 2. 3. 4. 5. 6. 7.

b. c.

Prepare your gelatin according to the package directions but do not refrigerate it yet. Let it cool down enough that you can stick your finger into it. Label your plastic cups from 1 to 3. Half fill your plastic cups with your gelatin. Create a data table like the one below. Make your first observations. Place your cups in the refrigerator. Make observations after one hour in the refrigerator. For the experiment: 1. In the first cup do not add any pineapple. 2. In the second cup only add fresh pineapple. 3. In the third cup add cooked pineapple. Record your observations after adding pineapple Clean up

Observation Table: Write a descriptive title here

Cup Observations number before refrigeration

1

Observations after 1 hour of Observations after refrigeration addition of Pineapple

Still a completely liquid Liquid State, state, bubbles have Bubbles at the settled at the top and top. disappeared

No change

2

Liquid State, -Complete liquid state Bubbles at the -bubbles have settled at top. the top & disappeared

3

Liquid State, Bubbles at the top.

-Complete liquid state -Bubbles have settled at the top & disappeared

-Pineapple slowly starting to liquefy top layer of the Jell-O

-Pineapple is not changing the state of the Jell-O -pineapple sitting on top.

Results: 1. 2.

Complete the data table. What did you observe before putting it in the refrigerator?

My observations before putting the Jell-O in the fridge; it is a red colour from the strawberry flavouring and it is completely liquid. Bubbles formed at the top of the JellO from mixing the cold and hot water together. 3. What did you observe after one hour in the refrigerator? My observations after checking on the Jell-O one hour after putting it in the fridge was not a lot different from my observations of it’s begging state. The bubbles disappeared as everything is starting to settle, it was still pretty liquid, but could tell it was starting to form into a Jell-O. 4. What did you observe after adding the fresh pineapple? Why does this happen? After observing the cup of Jell-O with added fresh pineapple, I noticed a layer of liquid on the top and the pieces of pineapple sitting in the liquid. At that point, it was clear to me that the enzymes in the pineapple were slowly liquefying the Jell-O it was coming in contact with. This happens because the bromelain in the pineapple, being a proteolytic enzyme, breaks down the peptide bonds in the collagen that turn the liquid Jell-O into a wiggly mass of semi-solid protein. The pieces of protein gradually release water, retuning it back to a liquid state. 5. What did you observe after adding the cooked pineapple? Why does this happen? After adding and observing the cooked pineapple in the Jell-O, it was evident that it did not liquefy the Jell-O like the uncooked pineapple did. This is because the bromelain enzymes in the pineapple were inactivated when the pineapple was boiled

of the stove, due to the high heat. 6. Does gelatine contain protein? Yes, gelatin is made out of an animal protein called Collagen. It is mostly protein (9899%). Conclusion:

In conclusion, I learned that Bromelain is a mixture of enzymes that digest proteins and that gelatin is made up of mostly Collagen, which is a protein. Therefore, if you mix pineapple, which contains bromelain and Jell-O, which contains a protein, the bromelain will begin to break down the peptide bonds in the collagen proteins, as the proteins are cut up, they slowly release the trapped water, returning the Jell-O to its beginning liquid state.

What to Submit: 1. 2. 3.

A completed data table. Answers to the questions from the results. A conclusion for what you learned....