Structural Adaptation of Leaves for Photosynthesis and Gaseous Exchange

 

-photosynthesis require light, CO2 and H20 as substrate

1) Thin flat shape :

light :

• Maximized the area explosed to light
• Minimized the distance of light to mesophyll cell

CO2 :

• Minimized the distance of CO2 to mesophyll cell

2) Epidermis :

light :

• thin layer
• transpiration, allow light to penetrate

water :

• covered by cuticle , reduce water loss

3) Palisade mesophyll cell :

light :

• closely packed
• lots of chloroplast

4) Spongy mesophyll cell :

CO2 :

• lots of air space

5) Stomata :

CO2 :

• mechanism controling gaseous exchange and water loss

Water :

• mechanism controling gaseous exchange and water loss
• located mainly at lower site

6) Vein :

• act as skeleton
• remove photosynthetic product

 

* think the structure of a leaf first