Aerobic respiration takes place continually in animals and plants. The process uses glucose and oxygen and releases carbon dioxide and water as waste products. Most of the chemical reactions involving respiration occur in the mitochondria and are controlled by enzymes.
Glucose + oxygen ----> carbon dioxide + water (+ energy)
C6H12O6 + 6O2 ------> 6CO2 + 6H2O
The energy released from respiration may be used by the organism to:
- Build smaller molecules into larger ones
- Provide muscles with energy to contract in animals
- Maintain a constant body temperature in colder surroundings in mammals and birds
- Build sugars, nitrates and other nutrients into amino acids and then proteins in plants
Investigations involving aerobic respiration usually measure the amount of carbon dioxide produced. Limewater can be used to test for carbon dioxide. Limewater turns cloudy in the presence of carbon dioxide. The quicker the limewater turns cloudy, the quicker the carbon dioxide is being produced. It is possible to detect a rise in temperature when respiration is occuring. If germinating peas are left in a thermos flask, the rise in temperature due to respiration can be monitored.
THE EFFECT OF EXERCISE ON THE BODY