F2 IS WS06 Answers

1st Term WS 06 Submission date：_____________ Name：______________________ Class & no.：2 _________(     )

7.3       How does our body obtain energy?

i      Words to know:

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

i      Fill in the blanks:

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 of high-energy food can make us become overweight.

8        The table below shows the differences差異 between respiration and burning:

	Respiration	Burning
Does a flame exist?	no	Yes
The process is…	much more complicated複雜	Less complicated
Takes place in…	Living cells	Air
Energy release is…	slower	much faster