Biology for CSEC

  1. What is photosynthesis?

    • Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy into chemical energy stored in glucose, using carbon dioxide and water as raw materials.

  2. What are the main components required for photosynthesis?

    • Light energy (often from the sun)

    • Water (H2O)

    • Carbon dioxide (CO2)

    • Chlorophyll (the green pigment in plants)

  3. What is the overall chemical equation for photosynthesis?

    • The general equation is:
      6CO<em>2+6H</em>2O+lightoC<em>6H</em>12O<em>6+6O</em>26CO<em>2 + 6H</em>2O + light o C<em>6H</em>{12}O<em>6 + 6O</em>2

  4. In which part of the plant does photosynthesis mainly take place?

    • Photosynthesis primarily occurs in the leaves, specifically in the chloroplasts, which contain chlorophyll.

  5. What are the two main stages of photosynthesis?

    • The light-dependent reactions

    • The light-independent reactions (Calvin cycle)

  6. What occurs during the light-dependent reactions?

    • Light energy is captured by chlorophyll and used to split water molecules, releasing oxygen and creating energy-rich molecules (ATP and NADPH).

  7. What occurs during the Calvin cycle?

    • ATP and NADPH produced in the light-dependent reactions are used to convert carbon dioxide into glucose.

  8. Why is photosynthesis important for life on Earth?

    • Photosynthesis is crucial because it produces oxygen, which is essential for the respiration of most living organisms, and it forms the base of the food chain, providing energy for heterotrophic organisms.