Figure 1.
Site of activity of herbicides that inhibit Photosynthetic light reactions.
The white arrows indicate the movement of electrons as a result of the capture of light energy; the colored arrows, the vertical flow of the electrons. The dashed line originated in Fd represents the cyclic route. The blocking sites of the electrons flow by the herbicides, are indicated as H.

Abreviations:
P680: Photosystem II reaction center
Q: Primary electron acceptor
B: Secondary electron acceptor
PQ: plastoquinone
CYT f: Cytochrome f
CYT b6: Cytochome b6
PC: plastocyanine
P700: Phtosystem I reaction center
Fe-S: Proteins that contein iron joined to sulphur atoms
Fd: Ferridoxine
NADP: nicotinamide adenine dinucleotide phosphate
ADP: Adenosine diphosphate
ATP: Adenisine triphosphate