NAME___________________________ DATE___________________ HOUR___________________

BIOLOGY I

HELLO HAWAII

CHEMISTRY OF LIFE - 2

PURPOSE: To investigate enzyme activity.

MATERIALS NEEDED: Test tubes and tube rack hot gelatin, fresh pineapple, canned pineapple, ice water bath, frozen pineapple, knife to cut pineapple

NEEDED BACKGROUND INFORMATION:

The enzymes in some tropical fruits can break down protein. For example, meat tenderizers have the enzyme, papain, that breaks down some of the fiber in meat. We use it then to soften up a tough piece of meat. The papain comes from the papaya fruit. Pineapple has a digestive enzyme called bromelin that has a similar effect on proteins. The bromelin enzyme is named after the group of plants that pineapples belong to, they are the Bromeliads.

Enzymes are temperature dependent. In other words, each enzyme has a temperature at which they work the best.

PROCEDURE ONE:

    1. Get all of the equipment needed
    2. Label your tubes 1-4
    3. Pour approx. 3 ml of gelatin into each tube
    4. Place FRESH pineapple in tube one
    5. Place FROZEN pineapple in tube two.
    6. Place CANNED pineapple in tube three
    7. Tube four will have only gelatin in it.
    8. Gently mix the contents of the four tubes.
    9. Place all four tubes in the ice water bath.
    10. When tube four has gelled completely, check your results.
    11. Record your observations in the data table

TUBE CONTENTS

OBSERVATIONS

FRESH PINEAPPLE

-

FROZEN PINEAPPLE

-

CANNED PINEAPPLE

-

JUST GELATIN

-

 

 

 

ANALYSIS QUESTIONS

:

  1. Which group do enzymes belong in, the carbohydrates, the lipids, the proteins, or the nucleic acids?

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  2. Why did tube 4 contain only gelatin?

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  3. What could account for the different results in the tubes?

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  4. How could the canning process change the bromelin enzyme?

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  5. What could be done to fresh pineapple that would allow pineapple "Jell-0" salad to gel?

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  6. Design an experiment to find a temperature at which meat tenderizer works best. Be sure to include a control. (Use a separate piece of paper to make a rough draft of your experiment. Staple a word processed copy to this lab sheet.)