*Label the steps that occur in the process shown.
1. Water is split, providing electrons to replace those lost by PSII
2. Electrons are boosted to a higher state and accepted by a membrane protein
3. Electrons are passed down the electron transport chain, creating a proton gradient that fuels the production of ATP
4. Electrons leave photosystem I and are accepted by another protein
5. Electrons passed down another ETC, which leads to the production of NADPH (energy carrier)