Step 1: Light energy forces electrons to enter a higher
energy level in the two chlorophyll a molecules of photosynthesis II.
Step 2: Because molecules have been lost the chlorophyll
a molecules have undergone an oxidation reaction. Each oxidation reaction must be accompanied by a reduction reaction.
So, a substance have to accept electrons that the chlorophyll a molecules have lost.
Step 3: The primary electron acceptor donates that
electron to the first of the series of molecules located in the thylakoid membrane. Those moles are called an electron
Step 4: Light is absorbed by photosytem I, which
happens at the same time that light is absorbed by Photosystem II.
Step 5: NADP+ is reduced to NADPH by a reaction called