S4.1.6 For the adult
Photosynthesis
A tree grows from a seed to many tonnes of wood. Where does all that material come from?
What this chapter teaches
Photosynthesis makes glucose and oxygen from carbon dioxide and water, using the energy of light absorbed by chlorophyll. Its rate is limited by whichever of light, carbon dioxide or temperature is in shortest supply. Too high a temperature denatures the enzymes.
Three questions to ask
There is no one right wording. Listen for the idea.
- What goes into a leaf in photosynthesis, and what comes out?
- What does limiting factor mean? Can you give an example?
- Why does the rate fall when the leaf is too hot?
After the chapter, the learner can
- Write the word and symbol equations for photosynthesis
- Explain how light, carbon dioxide and temperature limit the rate
What they copy into their notebook
Carbon dioxide + water → glucose + oxygen, using light and chlorophyll. 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂. The factor in shortest supply, light, carbon dioxide or temperature, limits the rate.