Rebecca Baldeosingh LAB #8
DATE: 25/11/2022
TITLE: Proteins
PROBLEM STATEMENT / OBSERVATION:
"Jell-O is commonly used to describe any brand of gelatin. Gelatin is derived from collagen
which is a protein present in animal tissues such as muscle and bone.
When mixed with warm water and left to cool in the refrigerator, it becomes a wobbly jelly.
The proteins form a mesh which traps the water and any added flavours.
It is not recommended to add some fresh or frozen fruits such as pineapple, but canned
pineapple can be used.
Indra had a basket of fresh fruits which included a pineapple, a guava, an apple, a papaya, an
orange, and a mango. She wanted to make a bowl of "Jell-O" with all the fruits.
Plan, design and carry out an investigation which explains the recommendation on the gelatin
box and suggest which fruits Indra can use to make a bowl of Jell-O.
HYPOTHESIS: Fresh fruits containing protease enzymes cannot solidify in Gelatin.
AIM: To investigate if fruits containing proteases enzyme settle in gelatin.
APPARATUS AND MATERIALS:
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Pack of Jell-O
Fresh fruits (Pineapple, guava, apple, papaya, mango and orange)
10 ml Measuring cylinder
Beaker
6 Petri dishes
Scalpel
Cork borer
Ruler
White tile
Forceps
Stopwatch
VARIABLES:
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MANIPULATING VARIABLE:
1. The type of fruits being tested.
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CONSTANT VARIABLES:
1. Amount of Jell-O used.
2. Length of time taken for Jell-O to solidify.
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RESPONDING VARIABLE:
1. Solidity state of fruits in the Gelatin.
METHOD:
Label pert dishes “A”, “B”, “C”, “D”, “ E”, and “F” respectively.
Use the cork borer to obtain five strips of each fruit.
Using a scalpel, carefully trim each strip to a length of 20mm.
Prepare the Jell-O according to the package directions in a beaker.
Measure 4 ml of Jell-O mixture and place in every petri dish.
Place the pineapple strips in petri dish label “A”, the guava strips in “B”, the apple strips
in “C”, the papaya strips in “D”, the mango strips in “E’, and lastly, the orange strips in
“F” using forceps.
7. Carefully place all petri dishes in refrigerator for five (5) hours.
8. Flip the petri dish upside down over the sink and make observation
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EXPECTED RESULTS:
TITLE: TABLE SHOWING OBSERVATIONS (SOLIDITY) OF THE DIFFERENT TYPES
OF FRUITS IN GELATIN.
Petri Dish
A
Different Fruits Used
1. Pineapple
B
2. Guava
C
3. Apple
D
4. Papaya
E
5. Mango
F
6. Orange
Observations Made
It is expected that the pineapple, guava, papaya, and mango in petri dishes “A”, “B”, “D”, and
“E” will not set, and the apple and orange in petri dishes “C” and “F” will set in the Jell-O.
INTERPRETATION:
Jelly contains gelatin which partially consists of protein molecules. Pineapple, guava, papaya,
and mango will not solidify in Gelatin because they all contain proteases enzymes which break
down these protein molecules, making them smaller, so they can't tangle up, which stops the
jelly setting. However, the apple and orange will solidify because they do not contain proteases
enzymes, so the protein molecules tangle up as they cool down trapping the water to make a
solid
LIMITATIONS:
1. Temperature of the refrigerator.
PRECAUTIONS:
1. Ensure that warm water is used when preparing Jell-o.
2. Taken readings at eye level of the meniscus to avoid parallax errors.
EXPECTED CONCLUSION / STATEMENT OF VALIDITY:
Fresh fruits containing protease enzymes (pineapple, guava, papaya, and mango) does not
solidify in Gelatin, then the hypothesis is accepted.
REFLECTION:
From this lab, I now have a greater knowledge of protease enzymes in the human body and
what an important role they play. Protease enzymes are responsible for breaking down proteins
in our food into amino acids. Then different enzymes join amino acids together to form new
proteins needed by the body for growth and repair.