- Photosynthesis -
Site of Photosynthesis.
Within eukaryotic plants this is the main site of photosynthesis // Within the chloroplast of cellular organelles.
Structure of the leaf.
- Large surface area = more sunlight is absorbed
- Arrangement of leaves = avoids overlapping // leaves do not overshadow each other.
- Thin // diffusion distance is kept short = light absorbed within few micrometers
- Transparent cuticle and epidermis let light through to photosynthetic mesophyll cells
- Long, narrow upper mesophyll cells packed with chloroplast = collecting sunlight.
- Numerous stomata = gas exchnage // short diffusion pathway from the mesophyll cells
- Stomata open and closes = result of light intensity
- Many air spaces in lower mesophyll layer to allow rapid diffusion in the gas phase of carbon dioxide and oxygen.
- Network of xylem = brings water to leaf cells // Phloem = carries away the sugar (product of photosynthesis)
There are 3 stages in photosynthesis.
- Capturing the light energy
- Light-dependent reaction
- Light Independent reaction
Structure of chloroplast and its role.
The grana = 100 discs-like structure = thylakoids // light dependent stage takes place here.
The stroma = fluid filled matrix // light independent stage occurs here // number of other structures, for example, starch grains.
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