TITLE: Enzymes

OBSERVATION: It was observed that when fresh fruits were placed into the gelatin mix it didn’t solidify properly.

HYPOTHESIS: The enzymes contained in pineapples prevents gelatin from solidifying completely.

AIM: To determine if the presence of fresh fruit gelatin from solidifying.

APPARATUS AND MATERIALS: pineapples, water, Bunsen burner, tripod stand, three beakers, 3 packets of gelatin, scalpel, tape, marker, stopwatch

METHOD:

1. Label the three beakers, A,B and C.2. Cut the fresh pineapples into sixteen, 1cm cubes.3. Place a beaker fill with water on to the tripod stand to boil.4. Place eight cubes of pineapples into the boiling water to boil.5. Then heat approximately ¾ cup of water separately for the gelatin mix.6. In the beaker, sprinkle one packet of gelatin over 1/4 cup (50mL) cool liquid. 7. Let stand for 1 minute. Add 1/4 cup (50mL) boiling water, stir constantly until

granules are completely dissolved.8. Then place eight of the freshly cut pineapples into beaker ‘A’ which contains a packet

of gelatin mix.9. Then take the other 8 pineapples into beaker ‘B’ which also contains a packet of

gelatin mix.10. Beaker ‘C’ should be left as with the gelatin mixture only.11. Then place the three beakers into the fridge.12. Observe every twelve minutes within an hour and then record the findings in the table

below.

VARIABLES:

Independent variables-The state of the pineappleDependant variables-The time taken for the gelatin to solidify.Controlled variables-Temperature of the pineapple when added to the gelatin mixture.

PRECAUTIONS: 1. Ensure equal amounts of gelatin is used in the three mixtures.2. Ensure that you do not disturb the mixture whilst in the fridge.

EXPECTED RESULTS: The mixture which contains the freshly cut pineapples would prevent the gelatin from setting, the mixture which contains the pineapple which has been boiled will solidify properly and the mixture which contains only gelatin will set properly

EXPLAINATION OF RESULTS: Gelatin is primarily from a structured protein called collagen, which is extracted from bones and connective tissues of animals. Since the bromelain in fresh pineapple can digest the protein, the gelatin in Jell-O will not be able to set when mixed with it. When the pineapples have been boiled the enzymes in the pineapples

have denatured due to the fact that enzymes only work properly at an optimal temperature. The mixture which contains no fruits will set properly if it was mixed as directed.

TREATMENT OF RESULTS:

12 MINS

24 MINS

36MINS

48MINS

60MINS

BEAKER 'A'

BEAKER 'B'

BEAKER 'C'

ASSUPTIONS:

1. The pineapple and gelatin mixture would not solidify because of the protein eating enzyme found in pineapples

LIMITATIONS:

1. All three beakers should contain the same amount of gelatin mixture.2. Fresh pineapple must be used