BioInteractive Photosystems I and II

Question 1

What is the primary electron donor in Photosystem II?

Accepted Answer

Water

Answer

Photosystem II oxidizes water molecules to extract electrons, releasing O2 as a byproduct through the oxygen-evolving complex.

Question 2

What is the designation of the reaction center chlorophyll in Photosystem II?

Accepted Answer

P680

Answer

The reaction center of PSII contains a special chlorophyll a molecule that absorbs light maximally at 680 nm, designated P680.

Question 3

What is the designation of the reaction center chlorophyll in Photosystem I?

Accepted Answer

P700

Answer

Photosystem I contains a special chlorophyll a molecule that absorbs light maximally at 700 nm, designated P700.

Question 4

In what order do electrons flow through the two photosystems during non-cyclic electron flow?

Accepted Answer

PSII → PSI

Answer

In linear (non-cyclic) electron flow, electrons move from water through PSII, then through the electron transport chain to PSI, where they are ultimately used to produce NADPH.

Question 5

Which photosystem contains the oxygen-evolving complex that splits water?

Accepted Answer

Photosystem II

Answer

Photosystem II contains the oxygen-evolving complex (OEC) that catalyzes the oxidation of water, extracting electrons and releasing O2.

BioInteractive - Photosynthesis BioInteractive Test Practice Test

BioInteractive - Photosynthesis BioInteractive Test Practice Test

BioInteractive Photosystems I and II