8 ORGANISMS REQUIRE A SUPPLY OF ENERGY AND MATERIALS FOR WHICH THEY OFTEN DEPEND ON, OR COMPETE WITH, OTHER ORGANISMS

Task 10

Materials and tools for a working group:

kitchen scales, tray, cutlery table knife, various kinds of food (beverages), calculator

This activity is directly related to the previous one. Its aim is to realize that every organism cannot take as much food as it wants. The task will be to find out how much of particular foods they could consume per day to cover energy demand. At the beginning, the teacher shows pupils a table representing the daily average energy intake of people by age. He then discusses with them what would happen if a person received less or more energy than his body would need. The discussion is directed at the fact that with less income we would not have energy and with higher income we would gain more weight – the body stores energy in its reserves.


	4–7 years	7–10 years	10–13 years	13–15 years	15–19 years
Kcal	1.400 - 1.500	1.700 - 1.900	2.000 - 2.300	2.200 - 2.700	2.5000 - 3.100

He will then provide pupils more food (e.g. apples, lettuce, potatoes, cheeses, biscuits, etc.), kitchen scales, a calculator and calorie tables. Energy values are given on the food packaging. In the case of e.g. vegetables and fruits, the values are provided by the teacher or they can be found on the Internet).

The task will be to compose the daily energy intake using the provided food. That is, if a 10-year-old child is to receive about 1900 kcal per day, pupils should weigh enough food to cover that income per day. Then, together with the teacher, they calculate how much food they should eat to meet the daily energy intake limit. At the end, they calculate the energy value of the food using a calculator and compare it to the recommended daily intake.

In this way, pupils will see how much energy the investigated food provides – they will find out that some foods give us a lot of energy in small quantities and vice versa. In the next activity, the teacher can offer pupils to similarly investigate beverages. Pupils are asked to compose a set of food and beverages that would cover their entire energy requirement per day. The teacher should remind the pupils that the more they move during the day, the more energy they spend. Therefore, they should receive more energy than during the day when they sit all day.