For each four photons absorbed by PSII , eight protons are pumped into the lumen .
Of the proteins that participate in noncyclic photophosphorylation , photosystem II ( PSII ) , plastiquinone , and cytochrome b f complex directly contribute to generating the proton gradient .
For each four photons absorbed by PSII , eight protons are pumped into the lumen .
Of the proteins that participate in noncyclic photophosphorylation , photosystem II ( PSII ) , plastiquinone , and cytochrome b f complex directly contribute to generating the proton gradient .