Chapter 8 Study Questions

  1. The term “dark reactions” was used for many years to describe the reactions for incorporating CO2 in photosynthesis. Why was this term considered appropriate at the time and why is it now considered inappropriate?

    Textbook Reference: Introduction, pp. 203–204

  2. There is current concern that the level of CO2 in the biosphere is increasing due to the burning of fossil fuels. If the level of atmospheric CO2 were to double, how would the following parameters be affected? Explain your answers.
    1. Rate of oxaloacetate synthesis in C4 plants
    2. Rate of 3-phosphoglycerate synthesis in C3 plants
    3. Rate of photorespiration in C3 plants
    4. Yield of wheat in Kansas
    5. Temperature of San Francisco Bay

    Textbook Reference: Chapter 8, pp. 203–241

  3. Photorespiration is generally considered to be a wasteful process that decreases the yield of C3 plants. Under what conditions is the role of photorespiration minimized in plants?

    Textbook Reference: The C2 Oxidative Photosynthetic Carbon Cycle; pp. 211–217

  4. How does C4 photosynthesis differ from C3 photosynthesis? What are the additional metabolic costs?

    Textbook Reference: Inorganic Carbon–Concentrating Mechanisms: The C4 Carbon Cycle, pp. 222–224

  5. How does CAM metabolism differ from C3 metabolism and from C4 metabolism? What are the additional metabolic costs?

    Textbook Reference: Inorganic Carbon–Concentrating Mechanisms: Crassulacean Acid Metabolism (CAM), pp. 228–230