Lesson 6: Steps of the Light Dependent Reaction (Part 1)

Steps of the Light Dependent Reaction

1. Light energy is absorbed by photosystem II and the electrons are “excited”, they move down the electron transport chain into photosystem I.
   • The photosystems are photoionised - they lose or gain electrons
2. The electrons that left photosystem II must be replaced.
   • Photolysis occurs - light energy splits water into protons, electrons and oxygen
   • [katex] H_2O \rightarrow 2H^+ + \frac{1}{2}O_2 [/katex]