The figure in this exercise shows the topology of a phototrophic membrane with its light harvesting pigments and the electron transporting and proton translocating coenzymes for the conversion of radiation energy into ATP.

Fill in the missing membrane components and the electrons and protons which get moved across the membrane.

Remember:
Photon-driven electron transport leads to proton translocation across the membrane of phototrophic microorganisms which creates a proton motive force (pmf). A proton-driven ATP-ase phosphorylates ADP to ATP thus conserving the originally harvested radiation energy in a biochemically usable form. In addition, the formation of reducing equivalents (e.g. NAD(P)H) is coupled to reversed electron transport. Certain phototrophs are able to use organic substrates, like succinate or malate as sources of electrons, others use H₂S, a number of oxidizable sulfur compounds or ferrous iron (Fe²⁺).

The following abbreviations are used in the figure:
e- Electron
H+ Proton
[H] Hydrogen atom (carries electrons)
Bphe Bacteriopheophytin
RC Reaction center
LH Light harvesting pigments
P870 Bacteriochlorophyll Pigment which absorbs radiation with wavelengths around 870 nm
Q Quinone, oxidized form
QH2 Quinone, reduced form
Cyt Cytochrome
ATP Adenosinetriphosphate
ADP Adenosinediphosphate
NAD(P)H reduced form of Nicotinamide adenine dinucleotide, (Nicotinamide adenine dinucleotide phosphate), respectively