Photosynthesis and Leaf Structure

What is photosynthesis?

The process by which plants use the sun's energy to convert carbon dioxide and water into glucose and oxygen

What is the formula for photosynthesis?

Carbon dioxide + water --> glucose + oxygen

CO2 + 6H2O --> C6H12O6 + 6O2

What are the three limiting factors?

1. Carbon dioxide concentration

2. Temperature

3. Light intensity

Draw the graph of CO2 and the Rate of Photosynthesis

WB

Draw the graph of light intensity and the Rate of Photosynthesis

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Draw the graph of temperature and the Rate of Photosynthesis

WB

Explain why the graphs of carbon dioxide concentration and light intensity plateaux

As the carbon dioxide concentration or light intensity reach their optimum levels, other factors may become limiting

This is why the graph plateaux

List the parts of the cross section of the leaf

1. Waxy cuticle

2. Upper epidermis

3. Pallisade cell

4. Vascular bundle( xylem and phloem)

5. Spongy mesophyll

6. Lower epidermis

7. Guard cell

8. Stomata

9. Air space

What are the features of the waxy cuticle?

1. Transparent to let sunlight through

2. Waterproof to prevent water from leaving the plant, not entering it

What are the features of the upper epidermis?

1. Transparent to let sunlight through the plant

What are the features of the pallisade cell?

1. Contains chloroplasts for photosynthesis

What are the features of the xylem?

1. Transports water from the roots to the leaves

What are the features of the phloem?

1. Transports glucose in the form of sucrose throughout the plant

What are the features of the spongy mesophyll cell?

1. Contains chloroplasts for photosynthesis

What are the features of the lower epidermis?

1. Transparent to let sunlight through the plant

What are the features of the guard cell?

1. Contains chloroplasts for photosynthesis

2. Controls the opening and closing of the stoma

What are the features of the stoma?

1. Allows carbon dioxide to enter the plant through diffusion

2. Allows oyxgen to exit the plant through diffusion

3. Allows water vapour to leave the plant through the transpiration stream

What are the features of the air space?

1. Allows carbon dioxide to enter the leaf and diffuse into the photosynthetic cells

2. The outer layer of the air space is moist, to make the diffusion and dissolving of the gases more easier

Describe how the leaf is adapted for photosynthesis

1. Leaves are broad to allow for greater sunlight absorption

2. Leaves are thin to allow the diffusion of gases to be more efficient

Describe how the leaf is adapted for gas exchange

1. The outer layer of the air space is moist, thereby allowing the diffusion and dissolving of gases to be more efficient.