Boundless Biology by Lukas Waller

3.4 - CAM and C4 plants

Listen Later

C4 Plants

  • Examples: Maize, sugarcane, sorghum.
    • Adaptation: Found in hot, dry environments to minimize photorespiration.
    • Key Enzyme: PEP carboxylase, which has a high affinity for CO₂ and does not react with O₂, reducing photorespiration.

      • Pathway:

      • CO₂ + PEP (3C) → Oxaloacetate (4C) → Malate (4C).
      • Malate is transported to bundle-sheath cells, where CO₂ is released for the Calvin cycle.



        • CAM (Crassulacean Acid Metabolism) Plants

        • Examples: Pineapple, cacti, succulents.
        • Adaptation: Found in arid environments; adapted to conserve water.
        • Stomata Behavior: Stomata open at night to minimize water loss.
        • Key Enzyme: PEP carboxylase, similar to C4 plants, used for initial carbon fixation at night.

          • Pathway:

          • CO₂ + PEP → Oxaloacetate (4C) → Malate (4C), which is stored in vacuoles as malic acid overnight.
          • During the day, malic acid is broken down to release CO₂ for the Calvin cycle.


            • ...more
            View all episodesView all episodes
            Download on the App Store
            Boundless Biology by Lukas WallerBy Lukas Waller