As sacrificial electron donor water is oxidized to molecular oxygen in green plants. This happens through a manganese cluster at the donor side of Photosystem II (PS II). This paper describes the design, syntheses and photoinduced electron transfer of supramolecular model systems which mimic some individual electron transfer steps at the donor side of PS II. In these systems, manganese complexes (to mimic the manganese cluster in PS II), and L-Tyrosine derivative (to mimic the Tyrosin_z in PS II) have been covalently linked to a ruthenium(II) tris-bipyridyl complex (to mimic the function of P₆₈₀ in PS II). It has been demonstrated that, in the presence of an external electron acceptor in solution, such systems can undergo an intermolecular electron transfer from the photoexcited state of Ru(II) to an acceptor, followed by a subsequent intramolecular electron transfer from the co-ordinated Mn complexes or the tyrosine unit to the photogenerated Ru(III), leading to oxidation of Mn complexes or generation of tyrosine radical and regenerating Ru(II). It was found that introduction of a tyrosine derivative between a manganese dimer and the Ru(II) photosensitizer can increase the intramolecular electron transfer rate. This closely mimics the similarity to the photoevents at the donor side of PS II.