Lab Report
Lab Report
Calculating Energy Content of Foods with a Calorimeter
Answer the following questions about the results of this activity. Record your answers in the
boxes.
Send your completed lab report to your instructor. Don’t forget to save your lab report to your
computer!
You will need the following table, information, and formula to calculate the information in the
lab activities:
Food
Fat*
Carbohydrates*
Beef
21
2
Bread
2
40
Celery
0
3
Chicken
11
5
*Grams of molecule per 100 grams of food
Protein*
21
7
0
29
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 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 caloric content of the carbohydrates, fat, protein, and nucleic acids
samples based on the table and information given above. Place the answers in the “Expected
Calories” columns.
Sample
Carbohydrates
Fat
Protein
Nucleic
Acids
Readout
Calories
Expected
Calories
1. Is the calorimeter accurate enough for use in an experiment?
Explain.
Activity 2
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, protein, nucleic acids samples based on the table and formula
given above. Place the answers in the “Expected Calories” columns.
Food
Weight in Grams
Readout Calories
Expected
Calories
Beef
Bread
Celery
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
Record your data from Activity 3 in the boxes below. Enter the data you collected for the
samples you tested (beef, bread, celery, chicken) in the columns for the appropriated animals
(cow, dog, rat, human).
Sample
Beef
Bread
Celery
Chicken
Cow
Dog
Rat
Human
4. Explain why there might be differences in the calorie calculations for
the different animals.
5. Explain why it is important to know that animals vary in their ability
to obtain calories from food.