In this chapter we explored two important cell activities, photosynthesis and respiration. Much of our understanding about scientific processes, including those of cell activities, is based on empirical evidence (based on observations) and experimental data. All observations must be interpreted; scientists need imagination and creativity to make sense of what they observe. The experiments in this chapter tell us something about the factors that affect photosynthesis and respiration. Question: Explain why the ability to think creatively and imaginatively is very important in the work of a scientist.
Chapter Summary
1. Cells carry out many chemical and biological processes. 2. Photosynthesis is the way that plant cells use the sun’s energy to produce glucose. 3. Photosynthesis is carried out in green plants. Green plants contain a pigment called chlorophyll which is found in chloroplasts.
4. Plant leaves are specially adapted for photosynthesis – they are flat, thin and contain stomata.
5. Word equation for photosynthesis: Light energy Carbon dioxide + Water Chlorophyll 6. Chemical equation for photosynthesis: Light energy 6CO2 + 6H2 O Chlorophyll
7. Glucose is transported around the plant in phloem cells. It is stored as starch. 8. Water is transported in xylem cells. 9. Respiration is a chemical reaction that occurs in a cell to release energy from glucose.
10. Respiration is carried out in the cells of all living organisms. 11. Aerobic respiration uses oxygen.
