Light stage

Light stage

1. Light Dependent (grana of chloroplast)

2. Ingredients: Water, Light, Chlorophyll

3. 1. Light is absorbed

   • Chlorophyll
   • Photolysis

4. 2 Pathways

   • Pathway 1 (cyclic)
     • electrons absorb the light energy
       • high energy electrons transferred along electron aceptors and back to chlorophyll
         • as it moves excess energy is released which is used to make ATP from ADP
   • Pathway 2 (non-cyclic)
     • 2 electrons absorb light energy
       • high energy electrons do not return to chlorophyll
         • as it moves, excess energy is released which is used to make ATP and ADP
           • the electrons combine with NADP+ and a proton to form NADPH

5. 3. Products

   • ATP: gives energy to dark stage reactions
   • NADPH: supplies protons and enegised electrons for dark stage reactions
   • O2: respiration/ released to atmosphere