What are the key steps in the light dependent reaction of photosynthesis?

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1. Light energy from the Sun excites electrons in chlorophyll and the excited electrons are emitted.

2. The chlorophyll molecule is now positively charged and chemically less stable. The lost electrons get replaced with electrons released from the photolysis of water: 2H2O --> 4H+ + 4e- + O2.

3. The excited electrons pass through the electron transport chain, a passage involving a series of redox reactions. This occurs in the thylakoid membranes.

4. At each transfer, energy is released and is used to combine

ADP + Pi -->ATP 

5. NADP is the final electron acceptor and gets reduced to form NADPH. This goes on to be used in the light independent reaction of photosynthesis.

6. Oxygen is a by product of this reaction and can either be used in aerobic respiration of the plant, or it can diffuse out as a waste product.

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