Light Dependent Stage

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1. Light strikes photosystem II, exciting a pair of electrons that leave the cholorophyll molecule from the primary pigment reaction centre.

2. Electrons pass along a chain of electron carriers and the energy released is used to synthesise ATP

3. Light has also struck photosystem I and a pair of electrons has been lost.

4. These electrons, along with protons in the stroma (which may have diffused from the thylakoid space through ATP synthase) join NAPD, which becomes reduced NADP (NADPH+)

5. Electrons from photolysed water replaced those lost by the oxidised chlorophyll in PSII

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