This paper examines the temporal evolution of an electron in a photosynthetic reaction center. A model based on self-consistent quantum-mechanical equations is suggested to describe the picosecond transfer of an electron from an excited primary donor, the excited bacteriochlorophyll dimer (P*), to bacteriopheophytin (H). This transfer is shown to have an oscillation behavior. The results obtained offer an explanation for oscillations in the emission kinetics of the primary donor excited state.