How do Enzymes Work? The Gene School

Purpose:
The purpose of this lab is to show how enzymes work. The enzymes in the fresh pineapple will break down the proteins (gelatin) in the Jell-O™, as will the enzymes in the soap. The proteins are made of amino acids, which form chains. When these chains are cut apart by the pineapple enzymes, the Jell-O™ can no longer hold its shape.

Supplies:
One fresh pineapple
liquid detergent that contains enzymes (may try more than one)
Any type of gelatin product (Jell-O™, any flavor)

Jell-O™ Pans
Before starting, make up gelatin product in several containers, according to package directions, and cool until set.
Cut a piece of the ripe pineapple.
 Cut up Pineapple
Pineapple in Jell-O™
Place the pineapple in one of the containers of Jell-O™ and put several drops of the detergent in the other.
 Soap on Jell-O™
Waiting...
You may have to wait for several hours.
Jello Slop
Observe what happens and record the results.
 Jello Slop

 


Results, Questions:
1.What is in the pineapple that made the Jell-O™ melt? (enzymes)

2. What is in the detergent that made the Jell-O™ melt? (enzymes)

3. What is in the Jell-O™ that melts? (Jell-O™ becomes solid when proteins bond together and hold the solution in a semi-solid state; when enzymes from the pineapple or soap are introduced, they cut the bonds between the proteins and cause the Jello-O™ to return to its liquid state)

4. Have you read the directions on a box of Jell-O™ about not putting fresh pineapple into it? Now do you know why?

5. Why does the detergent have enzymes in it? What would you expect the enzymes in detergent to break down? (the detergent contains enzymes that cut grease, helping to remove it from the clothes and making your clothes cleaner)

6. What other fruits would have the same effect on the Jell-O™ (because of similar enzymes)? (Fresh kiwi, gingerroot, papaya, figs, and guava all have the same effect on Jell-O™)

Applications:
1. Think of the bricks that make up a house. If someone tears down the bricks, does the house look the same? Are the bricks still there, though? This is like the proteins in Jell-O™.



2. What else do enzymes do in the body?


Experiment from The Natural History of Genes:
http://raven.umnh.utah.edu/new/projects/pineapple/pineapple.html

and

Access Excellence - GENETECH
http://www.gene.com/ae/AE/AEC/AEF/1996/thompson_jell-o.html