CP Biology
Name: ______________________________
Scorese
Per ____
Virtual Calorimeter Online Lab
Calculating Energy Content of Foods with a Calorimeter
http://www.wiley.com/college/trefil/0470118547/vdl/lab_calorimeter/
Answer the following questions about the results of this activity. Record your
answers in the boxes. START BY Clicking on the FOLDERS
Introduction: Objectives and Lab Overview
1. Where do organisms get the potential energy needed to convert to kinetic
energy?
2. Compare how plants and animals store their potential energy.
3. Click on Objectives Page. What are the objectives of this lab?
4. Click on the Lab Overview Folder. How is potential energy in food
measured?
5. What is a calorimeter? How does it work?
6. What does a Calorie measure?
7. “In Effect,” what does a calorimeter measure?
8. Which organic molecule has the most calories per gram?
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Info and Formulas: For This Lab Activity You WILL NEED the
following table, information, and formula to calculate the information in the lab
activities:
Food
Fat*
Carbohydrates*
Protein*
Beef
21
2
21
Bread
2
40
7
Celery
0
3
0
Chicken
11
5
29
*Grams of molecule per 100 grams of food
Calories per gram of food molecules:
 Carbohydrates: 1 gram = 4 calories
 Fat: 1 gram = 9 calories
 Protein: 1 gram = 4 calories
 Nucleic Acids: 1 gram = 4 calories (rarely broken down for energy)
Formula for calculating the expected calories in a food (nucleic acid content is
negligible):
Total Expected Calories of sample:
(Grams of sample/100 grams x grams of fat per 100 grams of food x 9 calories) +
(Grams of sample/100 grams x grams of carbohydrates per 100 grams of food x 4 calories) +
(grams of sample/100 grams x grams of protein per 100 grams of food x 4 calories)
Activity 1 – Calibration
Record your data from Activity 1 in the boxes below. Enter the data you collected for the samples
you tested (carbohydrates, fat, protein, nucleic acids) in the “Readout Calories” columns. Then
calculate the theoretical (expected) caloric content of the carbohydrates, fat, protein, and nucleic
acids samples based on calorie information given above. Place the answers in the “Expected
Calories” columns.
Sample
Carbohydrates
Fat
Protein
Nucleic
Acids
Readout
Calories
Expected
Calories
2
1. Is the calorimeter accurate enough for use in an experiment?
Explain.
Activity 2- Calculating Food Calories Record your data from
Activity 2 in the boxes below. Enter the data you collected for the samples you tested
(beef, bread, celery, chicken) in the appropriate columns (weight in grams, readout
calories). Then calculate the theoretical caloric content of the food based on its
composition of carbohydrates, fat, and protein and its calories/ gram. Use the Info table
and formula given above. Place the answers in the “Expected Calories” columns. The
first one was done for you.
Food
Beef
Weight in Grams
Readout Calories
Expected
Calories
130/100= 1.3
Fats: 1.3 x 21 x 9=245.7
Carbs: 1.3 x 2 x 4=10.4
Prot: 1.3 x 21 x 4 = 109.2
Total Calories= 365
Bread
Celery
3
Chicken
2. Explain why the grams of the nutrient molecules in a food do not add
up to the total gram weight of the food.
3. Explain why the calorimeter value varied from the expected caloric
content calculated for each food.
Activity 3- Comparison of Calories in Different
Animals
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Enter the Expected Calories you calculated in Activity 2 and then run the Calorimeter to collect
data to Test how different animals utilized the four foods. Place your answers in the columns for
the appropriated animals (cow, dog, rat, human).
Sample
Beef
Bread
Celery
Chicken
Cow
Dog
Rat
Human
Expected:
Expected:
Expected:
Expected:
Read out:
Read out:
Read out:
Read out:
Expected:
Expected:
Expected:
Expected:
Read out:
Read out:
Read out:
Read out:
Expected:
Expected:
Expected:
Expected:
Read out:
Read out:
Read out:
Read out:
Expected:
Expected:
Expected:
Expected:
Read out:
Read out:
Read out:
Read out:
4. Explain why there might be differences in the calorie calculations for
the different animals. Refer to your data in your answer.
5. Explain why it is important to know that animals vary in their ability
to obtain calories from food.
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Conclusion:
What did you learn about energy and calories from this lab?
What did you learn about the way animals utilize calories?
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