Leaf Gas Exchange

• Structure of Leaf:

  • Palisade Mesophyll - where photosynthesis occurs
  • Spongey Mesophyll - air space
  • Stomata - Gas enters/exits, close at night
• Xerophytic Plants Adaptations:

  • Sunken Stomata - trap moisture, increase local humidity
  • Thicker Cuticle - reduce evaporation
  • Longer Root Network - reach more water
  • Curled Leaves - trap moisuture, increase local humidity
  • Hairs - trap moisture, increase local humidity
• Stroma are opened by ions (K+) which move in via active transport
• Stomata open due to guard cells bending due to becoming turgid
• Factors affecting Stomata:

  • Light
  • Temperature
  • Water