Question

In Photosystem II , the active chlorophyll is

• A. $P_{680}$
• B. $P_{700}$
• C. $P_{673}$
• D. $P_{720}$

Answer 1

The correct option is A $P_{680}$

Photosystem II (or water-plastoquinone oxidoreductase) is the first protein complex in the light-dependent reactions of photosynthesis. The reaction centre of Photosystem II also known as $P_{680}$ contains chlorophyll a molecules. The P in $P_{680}$ stands for pigment, where as the 680 is the wavelength in the visible spectrum at which its absorption is maximum.
$P_{700}$ is the reaction centre of Photosystem I which contains a chlorophyll a molecule that absorbs light best at 700 nm.