Question

List the events taking place in the photo-chemical phase of Photosynthesis.

Answer 1

 The photochemical phase of photosynthesis is light-dependent. A series of chemical reactions occur in quick succession initiated by light, therefore the phase is called photochemical phase. It takes place in chlorophyll-containing thylakoids of chloroplast.
It occurs in the following steps :

1. The chlorophyll on exposure to light energy becomes activated by absorbing photons.
2. This energy is used in splitting the water molecules (photolysis) as below:-
   H₂O ——> H⁺ + OH^–
3. OH^– ions through a series of steps produce water (H₂O) and oxygen (O₂). Water may be used inside the plant but O₂ released into the atmosphere.
4. H⁺ combines with CO₂ in dark reaction to produce glucose.