Question

multiple choice question
when an electron arrives at photosystem i from the first electron transport chain, what boosts the electron’s energy to a very high energy level?

the second electron transport chain

the splitting of an atp molecule

the absorption of another photon of light energy

the proton gradient established during the first electron transport chain

Explanation:

In photosynthesis, when an electron reaches photosystem I from the first electron transport chain, it needs additional energy. Photosystems absorb light energy (photons). The second electron transport chain is for electron transfer, ATP splitting isn't for boosting electron energy here, and the proton gradient is for ATP synthesis. So the absorption of another photon of light energy boosts the electron's energy.

Answer:

the absorption of another photon of light energy