S4.1.8 For the adult
Respiration
After I run, I keep breathing hard even though I have stopped. Why?
What this chapter teaches
Respiration is the reaction in every living cell that releases energy from glucose. With oxygen it makes carbon dioxide and water. Without oxygen it makes lactic acid in muscles, or ethanol and carbon dioxide in yeast and plants. After hard exercise oxygen is needed to break down the lactic acid.
Three questions to ask
There is no one right wording. Listen for the idea.
- Is respiration the same as breathing? What is the difference?
- What happens in the muscles in very hard exercise, and why do you keep breathing hard afterwards?
- Why does bread dough rise?
After the chapter, the learner can
- Compare aerobic and anaerobic respiration in animals, plants and yeast
- Explain why we breathe hard for a while after exercise
What they copy into their notebook
Respiration is in every cell and releases energy from glucose. Aerobic: glucose + oxygen → carbon dioxide + water. Anaerobic: muscles make lactic acid. Yeast and plants make ethanol and carbon dioxide. Breathing hard repays the oxygen debt.