Category: Curriculum Map

Introduction:
In nature there are enzymes called proteases that “digest” or degrade proteins. Some of these enzymes have been genetically engineered and added to our laundry detergents in the hope that they will “digest” the protein off of our clothing. Do they work? Do they assist in cleaning? In this experiment you can compare different detergents and their ability to “digest” protein.
What is gelatin? Gelatin consists of protein chains that are easily digested into their amino acid components. Gelatin is prepared from collagen, a protein found in animal tendons and skin and taken out during the meat rendering process. Boiling collagen reduces the  weight by about one-third and separates the protein strands by breaking bonds. When the boiled collagen is cooled, it does not revert back to collagen but sets to a gel we know as gelatin.

Purpose :
To test the effectiveness  of laundry detergent brands (and their enzymes) to digest protein (in the form of gelatin)

Prelab

Hypothesis:   ____________ will decompose more gelatin in millimeters than ______________.

Materials:
Gelatin in 4 test tubes  Wax Pencil/ Permanent marker
3 detergent brands
Distilled water
Test tube rack
Parafilm®
Ruler

Procedure:
Day 1
1. Pour 5 ml of melted gelatin into 4 test tubes. Let the gelatin solidify.
2. Make 10% solutions of the five non-liquid detergents selected for testing. (Mix 10 g of detergent in 90 mL of distilled water). Label the solutions carefully and note whether enzymes are listed as a component of each.
3. Mark the top level of the gelatin with a permanent marker. Add 15 drops of each detergent solution to the top surface of the hardened gelatin in a test
tube. To one tube add 15 drops of distilled water. Label carefully.
Day 2
4. After 24 hours examine the test tubes. Notice that the gelatin has been liquefied in some tubes.  Use a ruler to measure the depth of the liquefication. Measure from the mark where the hardened gelatin started down to where it is still hard. Measure to the nearest mm. Record.
Day 3
5. Measure the depth of liquefication again after 48 hours.

Data   1 data table, 1 graph (time vs. mm. liquefied)

Conclusion:

1. What is the job of enzymes?

2. Why do laundry detergents often contain enzymes?

3. Why was gelatin used in this lab?

4. How is gelatin made?

5.  Name each of the laundry detergents you used and describe the effect each one had on the gelatin.

6.  Did any of the laundry detergents contain enzymes? If so, which one(s)?

7. Was your original hypothesis correct? Explain.

Energy in Food Write Up

Introduction:

Use your lab and your textbook to locate and include the following information in your introduction.

• What organisms are capable of making their own food?
• What process do they use to do this?
• Where do these organisms get their energy for food-making?
• This energy is captured with the help of what pigment?
• This energy is stored in what organic molecules?
• Where exactly in the organic molecules is the energy stored and so it can be used again later? (Hint: Energized electrons form these and then energy is released again when they are broken.)
• What process takes place in plants & animals to release energy?
• What gas is required for the process to occur?
• When foods are “burned” in our bodies, where is the energy being released from? Where did this energy originally come from?
• What is the usable form of energy for our cells?
• Define calorimetry and explain how it can be used to measure energy stored in chemical bonds of food.

Hypothesis:

• Write a statement explaining that calorimetry can be used to detect the amount of energy stored in the chemical bonds of foods.

Materials:

In sentence form, write a statement listing the materials required for this lab.

Procedure:

• In paragraph form, write the procedures for completing this lab.

Results:

• Draw and fill in table 1 showing the results of burning
• Draw and fill in table 2 showing your data analysis for nut calorimetry
• Write out and answer the questions on the lab. Remember to write and underline the question, but do NOT underline the answer.

Conclusion: (Write in paragraph form.)

• Restate your hypothesis.
• Tell how were you able to measure the amount of energy in each nut
• Did all three nuts contain the same amount of food energy? Explain by giving data from your experiment..
• Explain why some foods contained more energy than others
• Tell where this energy originally come from and how it got into the nuts
• Explain any errors you might have made in lab that could have affected your results