The establishment of a pH-Gradient across the cytoplasmic membrane of denitrifying Pseudomonas stutzeri might involve the enzymes and coenzymes as outlined in the figure and proceed via the numbered steps. Enter the correct entity from the pull down menu for each number.

The following abbreviations are used in the figure

NADH Nicotinamide-adenine-dinucleotide
Fp Flavoprotein
Fe-S Iron-sulfur-protein
Q Ubiquinone
Cyt Cytochrome
e- Electron
H+ Proton