Main substance involved in transfer of electrons in photosynthesis is

Main substance involved in transfer of electrons in photosynthesis is Cytochrome.
In photosynthesis, the cytochrome complex functions to mediate the transfer of electrons and energy between the two photosynthetic reaction center complexes, Photosystem II and Photosystem I, while transferring protons from the chloroplast stroma across the thylakoid membrane into the lumen.
Cytochrome c4 functions as a physiological electron carrier in the photosynthetic electron transport chain in R. gelatinosus.