- Light Dependant Reaction
- Non-cyclic photophosphoryltion produces ATP, Reduced NADP and O2.
- Cyclic photophosphorylation only produces ATP. It only uses PSI, the elcetrons do not pass on NADP, they go back to PSI via electron carriers. This means the electrons can be recyled and repreatedly flow through the PSI producing a small amount of ATP.
- Light energy excites electrons in chlorophyll, it is asbsorbed by PS11, the electrons move to a higher energy level and move along the electron transport chain to PS1.
- 2) As electrons move away from PS11 they must be replaced, light splits water into electrons, protons and oxygen.
- 3) The excited electrons lose energy as they move along the transport chain. The energy allows protons to move into the thylakoid down the concentrationgradient into the stroma - this movement combines ADP and Pi.
- 4) The light energy then absorbed by PS1 excites the electrons to a new level, it is transported to NADP with a proton from the stroma to make reduced NADP.