Question 54
What are the important events and end products of the light reaction?
The important events of light reaction are
(i) Excitation of chlorophyll molecule to emit a pair of electrons and use of their energy in the formation of ATP from ADP + Pi. This process is called photophosphorylation.
(ii) Splitting of water molecule
(a) H2O⟶4H+4e−+O2↑ (b) NADP + 2H+⟶NADPH2
End products of the light reaction are NADPH and ATP.
Reducing power is produced in the light reaction i.e., ATP and NADPH2 molecules which are used up in dark reaction, O2 is evolved as a by-product by the splitting of water.