Define light reaction and dark reaction. | web4study

Define light reaction and dark reaction.


Photosynthesis is divided into two stages.

(i) Light Reaction 

(ii) Dark Reaction

Light Reaction:

Chlorophyll Captures the light energy and converts it into chemical energy through Photosystems two energy-rich compounds are formed:

(a) NADPH2 (b) A. T.P

Some light energy splits water into Oxygen and Hydrogen.

NADP + H+ + e -> NADPH2


Dark Reaction:

Dark Reaction is light independent.
ATP and NADPH2 synthesized above provide energy to make glucose by fixing CO2 and H2O. Fixation of CO2 and conversion into glucose occurs in the Chloroplast by a series reaction called Calvin Cycle. Glucose molecules are converted into starch and stored.

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