In both photosystem I and photosystem II, light energy is used to excite electrons. The two photosysterns were narmed in the order of their discovery, and not the order of their work in the light-dependent reactions. Photosystem Il comes first in the sequence of events that moves
electrons from water molecules to their destination, NADP. Hydrogen ions travel with the electrons, and they change NADP into NADPH. The
process is summarized in this diagram.
The concentration of hydrogen ions is greater inside the thylakoid than outside. Which reaction or set of reactions releases hydrogen ions
inside the thylakoid?
2*+2(NADP)+ d0>NADPH
To Light-
Independenm
w
Light
Light
Resctic
STROMA
OH
H
Ht
H*
Thy akoid
mernbrane
ATP
Electron caien
hase
To Light
Independent
systern
K Reactions
ptosyster
OH
o
OH
2H, O
THYLAKOID SPACE
4H