Indicate whether each of the following descriptions better applies to photosystem I (1) or photosystem II (2). Your answer would be a four-digit number composed of digits 1 and 2 only, e.g. 2212.
( ) It reduces plastoquinone.
( ) It uses a manganese cluster to oxidize water.
( ) It is confined to unstacked thylakoids.
( ) It contains the special pair P???.

Question

Indicate whether each of the following descriptions better applies to photosystem I (1) or photosystem II (2). Your answer would be a four-digit number composed of digits 1 and 2 only, e.g. 2212.
( )	It reduces plastoquinone.
( )	It uses a manganese cluster to oxidize water.
( )	It is confined to unstacked thylakoids.
( )	It contains the special pair P???.

Quizplus · Accepted Answer

Whereas photosystem I (with the special pair P₇₀₀) is confined to unstacked stroma thylakoids, the stacked grana thylakoids contain photosystem II (with special pair P₆₈₀). The excited P₆₈₀ chlorophyll in photosystem II withdraws electrons from water held by a manganese cluster linked to the protein. The electrons are eventually passed on to plastoquinone.

Indicate Whether Each of the Following Descriptions Better Applies to Photosystem