Fats-Protein Lab



Testing for Lipids

Directions: 1. Paste this half sheet in your notebooks (sideways). 2. Draw 7 small circles on your brown paper and label them for the foods listed in the chart below. 3. Rub a small amount of each item listed in the correct circle. 4. Wait about 15-20 minutes and record your results. 5. Fill in questions below on your notebooks.

|Food |Translucent spot present? |Fat present? Yes or no |

|1. Water | | |

|2. Cooking Oil | | |

|3. Mayonnaise | | |

|4. Peanut butter | | |

|5. Ketchup | | |

|6. Juice | | |

1. Describe how you tested for the fats in the foods above.

2. What was the indicator used?

3. What does a positive and negative result look like for presence of lipids?

4. Why is it helpful to first test a substance (oil) that you are told has fat in it?

5. Why is it helpful to compare the spot left by water to the spot left by something with fat?

6. How is fat used in the body?

7. List those foods tested that contain fat.

8. Your friend’s lunch bag has a large translucent spot on the bottom. How do you explain the spot?

Testing for Lipids

Directions: 1. Paste this half sheet in your notebooks (sideways). 2. Draw 7 small circles on your brown paper and label them for the foods listed in the chart below. 3. Rub a small amount of each item listed in the correct circle. 4. Wait about 15-20 minutes and record your results. 5. Fill in questions below on your notebooks.

|Food |Translucent spot present? |Fat present? Yes or no |

|1. Water | | |

|2. Cooking Oil | | |

|3. Mayonnaise | | |

|4. Peanut butter | | |

|5. Ketchup | | |

|6. Juice | | |

5. Describe how you tested for the fats in the foods above.

6. What was the indicator used?

7. What does a positive and negative result look like for presence of lipids?

8. Why is it helpful to first test a substance (oil) that you are told has fat in it?

5. Why is it helpful to compare the spot left by water to the spot left by something with fat?

6. How is fat used in the body?

8. List those foods tested that contain fat.

8. Your friend’s lunch bag has a large translucent spot on the bottom. How do you explain the spot?

Testing for Protein

Directions: 1. Paste this half sheet of paper in your notebook (sideways). 2. Compare the two sets of test tubes in the front of the room. The first set contains only the test item. In second set of test tubes an indicator (Biuret solution) has been added to the test item. Protein will turn dark brown, dark purple, or blackish in the presence of Biuret solution. 3. Record the results of the test. 4. Answer the following questions in your notebook.

|Tube number and contents |Color with Biuret solution? |Protein present? Yes or no |

|Water | | |

|2. Peanut Butter | | |

|3. Tuna | | |

|4. Cotton Balls | | |

|5. Dog Hair | | |

1. Why was water (not a protein) tested with and without Biuret solution?

2. Describe how to tell if a substance is a protein using this test?

3. What was the indicator used for the presence of protein?

4. What does a positive and negative result look like for the presence of protein?

5. List the substances tested that were proteins.

6. How are proteins used by living things – what do they do?

7. What element is present in protein that is not present in carbohydrates?

8. Give two examples of what the proteins called enzymes do in the human body.

Testing for Protein

Directions: 1. Paste this half sheet of paper in your notebook (sideways). 2. Compare the two sets of test tubes in the front of the room. The first set contains only the test item. In second set of test tubes an indicator (Biuret solution) has been added to the test item. Protein will turn dark brown, dark purple, or blackish in the presence of Biuret solution. 3. Record the results of the test. 4. Answer the following questions in your notebook.

|Tube number and contents |Color with Biuret solution? |Protein present? Yes or no |

|Water | | |

|2. Peanut Butter | | |

|3. Tuna | | |

|4. Cotton Balls | | |

|5. Dog Hair | | |

1. Why was water (not a protein) tested with and without Biuret solution?

2. Describe how to tell if a substance is a protein using this test?

3. What was the indicator used for the presence of protein?

4. What does a positive and negative result look like for the presence of protein?

5. List the substances tested that were proteins.

6. How are proteins used by living things – what do they do?

7. What element is present in protein that is not present in carbohydrates?

8. Give two examples of what the proteins called enzymes do in the human body.

Testing for Carbohydrates

Directions: 1. Paste this half sheet of paper in your notebook. 2. Compare the two sets of test tubes in the front of the room. The first set contains only the test item. In second set of test tubes an indicator (Iodine solution) has been added to the test item. Carbohydrates will turn blue-black when present. 3. Record the results of the test. 4. Answer the following questions in your notebook.

|Tube number and contents |Color with Iodine solution? |Carbs present? Yes or no |

|Water | | |

|2. Oats | | |

|3. Potato | | |

|4. Bread | | |

|5. Peanut butter | | |

1. What three elements are present in all carbohydrates?

2. What was the indicator used for the presence of carbs?

3. What does a positive and negative result for the presence of carbs look like?

4. Why are the terms mono, di, and poly used to describe the three types of sugar?

5. What are starches?

6. How would we test for them? Why is Iodine not a good indicator for starch?

7. How are carbohydrates used by the body?

Testing for Carbohydrates

Directions: 1. Paste this half sheet of paper in your notebook. 2. Compare the two sets of test tubes in the front of the room. The first set contains only the test item. In second set of test tubes an indicator (Iodine solution) has been added to the test item. Carbohydrates will turn blue-black when present. 3. Record the results of the test. 4. Answer the following questions in your notebook.

|Tube number and contents |Color with Iodine solution? |Carbs present? Yes or no |

|Water | | |

|2. Oats | | |

|3. Potato | | |

|4. Bread | | |

|5. Peanut butter | | |

7. What three elements are present in all carbohydrates?

8. What was the indicator used for the presence of carbs?

9. What does a positive and negative result for the presence of carbs look like?

10. Why are the terms mono, di, and poly used to describe the three types of sugar?

11. What are starches?

12. How would we test for them? Why is Iodine not a good indicator for starch?

7. How are carbohydrates used by the body?

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