Explain the modern concept of photosynthesis.

Explanation

1. Photosynthesis is an Oxidation and Reduction process.
2. Water is oxidised to release `O_(2)` and `CO_(2)` is reduced to form sugars. The first phase requires light and is called light reaction or Hill.s reaction.
I. Lightreaction: It is a photo chemical reaction whereas Dark reaction is a thermochemical reaction .
1. Solar energy is trapped by chlorophyll and stored in the form of chemical energy (assimilatory power ) as ATP and reducing power `NADPH + H^(+) . NADPH + H^(+)` alone is known as Reducing power.

2 Oxygen is evolved as a result of splitting of water molecules of light .
Light reaction is discussed in two phases :
II Dark reaction (Biosynthetic phase) : Fixation and reduction of `CO_2` into carbohydrates with the help of assimilatory power produced during light reaction . This reaction does not require light and is not directly light driven . Hence it is called as Dark reaction or Calvin - Benson cycle.