Question

a series of energy transformations occurs in psii, the etc, and atp synthase. place these events in the order they occur, starting with electrons being pulled out of water.
mechanical energy in atp synthase is transformed to chemical energy as atp is produced.
light energy in a photon of appropriate wavelength is transformed to chemical energy at psii, which transfers the chemical energy to the etc.
chemical energy is transformed to mechanical energy as the etc changes shape to pump protons.
mechanical energy in the etc is transformed to potential energy in a proton gradient.
electrical energy in the form of a flow of protons is transformed to mechanical energy as atp synthase spins.

Explanation:

1. First, light energy (photon) is transformed to chemical energy at PSII (photosystem II) as electrons are pulled out of water.
2. Then, the chemical energy is transferred to the ETC (electron - transport chain).
3. Next, the chemical energy in the ETC is transformed to mechanical energy as the ETC changes shape to pump protons.
4. After that, the mechanical energy in the ETC is transformed to potential energy in a proton gradient.
5. Then, the electrical energy (flow of protons) is transformed to mechanical energy as ATP synthase spins.
6. Finally, the mechanical energy in ATP synthase is transformed to chemical energy (ATP production).

Answer:

1. Light energy in a photon of appropriate wavelength is transformed to chemical energy at PSII, which transfers the chemical energy to the ETC.
2. Chemical energy is transformed to mechanical energy as the ETC changes shape to pump protons.
3. Mechanical energy in the ETC is transformed to potential energy in a proton gradient.
4. Electrical energy in the form of a flow of protons is transformed to mechanical energy as ATP synthase spins.
5. Mechanical energy in ATP synthase is transformed to chemical energy as ATP is produced.