Form 1 _5.3 Oxygen is needed for respriration

Respiration 有两种：

External respiration : Breathing
Internal respiration  : Process of oxidising

↓   ↓    ↓    ↓    ↓    ↓

Glucose + oxygen → energy + Carbon dioxide + water

Glucose from ( food )
Oxygen from ( Air )

Energy is used :

1. to carry out daily activities .
2. sythesis（制造） of liquid of lipid （脂肪）and protein .
3. enables movement.
4. basal metabolic rate ( minimum daily energy requirement ).