PROCEDURE

In this lab, you will be given an array of materials and you will be asked to design your own experiment to test the effect of pineapple on gelatin. The goal is to understand what is actually going on in the pineapple-gelatin mix at a chemical level as well as understanding what affects the function of enzymes.  This experiment can be completed individually or in groups.  The names of group members must be submitted and approved prior to beginning the tasks.

MATERIALS AVAILABLE

·         Fresh pineapple, canned pineapple, freshly cooked pineapple

·         Other tropical fruits such a papaya, kiwi

·         Jell-0 (any flavor)

·         Cold water

·         Hot water/hot water bath

·         Small containers such as disposable, plastic cups or petri dishes

·         Spoons, stirring rods

·         Refrigerator

·         Knife

·         Paper towels

STUDENT TASK

Design a controlled experiment that shows the effect of raw pineapple on gelatin. Make sure your experiment description includes the following:

a. A hypothesis. Remember hypotheses are written as “If…then” statements.

b. A detailed experimental design that includes:

1. The effect of fresh pineapple on gelatin.

2. The effect of frozen pineapple on gelatin.

3. The effect of canned pineapple on gelatin.

4. The effect of freshly cooked pineapple on gelatin.

5. A test to determine how gelatin behaves without any additives.

c. A data table

d. Write up a detailed experimental plan on the accompanying sheet of paper.

                1. Identify your controls, independent, and dependent variables

                2. State/list your procedural steps clearly.

e. You will be able to perform your experiment once you receive approval of your experimental  design from your teacher.

f. Conduct your experiment.

g. Analyze your results using the following questions as a guide.

• 1. Clearly describe the results of your experiment. In which test tubes did the gelatin jell, which did not.

• 2. Clearly explain the results of your experiment. Why did some test tubes of gelatin jell, why did others not. Be specific!

• 3. What is the enzyme in your experiment?

• 4. What is the substrate in your experiment?

• 5. What is (are) the product(s) in your experiment?

• 6. What type of organic molecule is gelatin?

• 7. What type of organic molecule is bromelain?

• 8. Why were the results of the freshly cooked pineapple different than the results of the fresh, raw pineapple? Be specific!

PUT IT ALL TOGETHER

                After discussing your results with your lab group, develop an argument that explains what happened with the Eagle Farm Stand and their fruit cups. Organize your thoughts in a claim, evidence, reasoning (CER) format.   (Students or groups could also submit a video recording showing and discussing each component of the CER Criteria. Some students may need a more detailed format to organize material. The teacher could provide an alternate science report template to students or groups that may need it.)