1. Biochemistry
S2 Science
Energy

2. In what way(s) is a human like a car?

3. What do these have in common?

4. Gravitational energy
Chemical energy
Kinetic energy
Elastic energy

5. Food contains chemical potential energy.
What questions could we be interested in asking to explore this further?
Can any of these questions be answered by carrying out an experiment?

6. Learning intention Success criteria
Know how the energy content of food can be determined by experiment.
Draw a labelled diagram showing how the experiment could be carried out.
Design a table which can be used to record the results of the experiment.
Select the equation/formula which allows the results of the experiment to be used to calculate the energy content of food.
Explain the meaning of each symbol in this equation. 1 2 3 4

7. Energy content of food 1
S2 Science
Energy

8. Eh = cmΔT
c = specific heat capacity of water (energy needed to raise the temperature of 1kg by 1ºC.
m = mass of water
ΔT = change in temperature of water

9. Key Question
How will you improve the reliability of your results.

10. Learning outcome Success criteria
Be able to carry out an experiment to determine the energy content of food.
Carry out the experiment safely for at least one food stuff.
Record all relevant information in an appropriate format.
Repeat the experiment twice.
Use your results to calculate the energy content of the food stuff you were investigating.

11. Energy content of food 2
S2 Science
Energy

12. Learning outcome Success criteria
Understand how the results of your experiment can be used and evaluated to give meaningful information about the energy content of food.
State why a direct comparison of the energy content of different foodstuffs cannot be made from the results.
Carry out calculations so that the energy content of different foodstuffs can be compared.
Explain why the results of your experiment aren’t accurate.

13. How can a fair comparison be made between different food stuffs?

15. Calculate the energy content of the foodstuff(s) you investigated…
per gram
per 100 grams
Get results from at least two other groups (per 100g) for the foodstuffs they investigated.
Average the results for each foodstuff.
Draw a bar graph of the averaged results.

16. Actual values Wattsits – …
What factors will have affected the accuracy of your result?

19. Calories
S2 Science
Energy

21. Learning outcome Success criteria
Understand what calories are.
Define the term “calorie”.
Calculate calories from joules and vise versa.

22. Calories
A calorie is the amount of energy, or heat, it takes to raise the temperature of 1 gram of water 1 degree Celsius.
One calorie is equal to joules.
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