The P680/P700 Special Pair Chlorophylls

The video tutorial explains the roles of P680 and P700 in photosystems, focusing on their unique properties as chlorophyll pairs that allow them to donate electrons effectively. It covers the process of charge separation, where light energy excites electrons, turning them into strong reducing agents. The tutorial also details the electron transfer process, highlighting the role of P680+ as a powerful oxidizing agent that replaces electrons using water, facilitated by the oxygen-evolving complex.

What is the unique property of the special pairs of chlorophyll molecules in photosystems?

• They can absorb more light than other chlorophylls.

• They can donate electrons more effectively due to their close proximity.

• They are located in the thylakoid membrane.

• They are responsible for the green color of plants.

What happens to an electron when it is excited by light energy in a photosystem?

• It moves to a lower energy state.

• It becomes a strong oxidizing agent.

• It becomes a strong reducing agent.

• It remains in the same orbital.

In the context of photosystems, what is an electron hole?

• A space where an electron is present, acting as an oxidizing agent.

• A space where an electron is present, acting as a reducing agent.

• A space where an electron is missing, acting as a reducing agent.

• A space where an electron is missing, acting as an oxidizing agent.

Which molecule acts as the electron acceptor in Photosystem 2?

• Pheophytin

• Chlorophyll

• Water

• Oxygen

What role does the oxygen-evolving complex play in the electron transfer process?

• It absorbs light energy.

• It stabilizes the chlorophyll molecules.

• It donates electrons to replace those lost by P680.

• It acts as an electron acceptor.