Karen A. Beitler
Name __________________
Outcome - graph of layers of lipids and protein in milk
Problem - to determine the differences in lipids and protein in milk
Hypothesis -
Procedure:
Materials: skim milk, 2% milk, whole milk (soy or organic can be added),
mini centrifuge tubes and centrifuge, see-through rulers, paper towel
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1. Pour 1mL of each milk into a labeled centrifuge tube, 2 per student pair
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2. Place centrifuge tubes in holders and compare layer of lipid at the top (lipids are less dense than water and will float)
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3. Examine the layers in the centrifuge tube
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4. Measure the height of each layer in the tubes for the different types of milk and record in a chart.
5.
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Open the tube and use your finger to scoop out the top layer - what does it feel like?
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6.
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Pour off the next layer onto a paper towel
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7.
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Examine what is left in the tube - what does this feel like?
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8.
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Answer the questions below and write a procedure for determining the components of each layer.
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9.
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Write a procedure for determining the macromolecules in each layer of milk.
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1. Procedure:
Answer the following questions on another sheet of paper;
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1. Were their differences in the amount of lipids in the different types of milk? Explain.
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2. What do lipids feel like? Why do you think so?
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3. Were their differences in the amount of water in the different types of milk? Explain.
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4. What does the water look like? Does this layer look the same in all samples?
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5. What color is this layer? Why do you think so?
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6. Were their differences in the amount of protein in the different types of milk? Explain.
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7. What do proteins feel like? Why do you think so?
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8. Suggest reasons for any differences you have observed.
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Graph the measurements in the layers seen in difference types of milk.
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Chart results of macromolecule tests.
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11. What does your graph show?
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12. Write the results of your macromolecule tests. and explain your results.