F2 IS QZ 04 ans

7.3

Word Translation (6 marks)

i    Write down the English terms of the following Chinese terms:

	Chinese term	English term
1	化學能	Chemical energy
2	能量值	Energy content
3	千卡路里	Kilocalories
4	千焦耳	Kilojoules
5	過重	Overweight
6	呼吸作用	Respiration

Fill in the Blanks (22 marks)

1      We need energy to carry out various activities. Energy is also needed for maintaining our body temperature, heartbeat and breathing. Such energy comes from the food we eat.

2      In our body, the chemical energy stored in food is released by a complex chemical process called respiration. It takes place in our living cells.

3      In respiration, food reacts with oxygen to form carbon dioxide and water. The energy released is used to support our body activities.

4      Write down the word equation of respiration.

        Food + oxygen -------------------------------à energy + carbon dioxide + water

5      In both burning and respiration, oxygen is consumed and carbon dioxide and water are produced. Energy is released faster in burning than in respiration.

6      The amounts of energy that the foods can provide are called the energy content.
It is measured in kilojoules (kJ) or kilocalories (kcal).

7      Eating too much high-energy food can make us become overweight.

Challenging Questions (Bonus 2 marks)

List TWO differences between respiration and burning.

A flame exists in burning but not in respiration. /

Respiration is a much more complicated process than burning. /

Respiration occurs in living cells while burning takes place in living cells. /

The energy is released much slower in respiration than burning. (Any TWO)