Primary charge separation in the photosystem II reaction center might take place on subpicosecond time scales. Typically, the time scales of environmental dynamics, such as protein reorganization, also occur in subpicosecond. To explore the potential causes for the subpicosecond charge separation, we theoretically investigate the interactions between environmental dynamics and quantum mixing that affect ultrafast photoinduced electron transfer. The time scales of environmental dynamics change the nature and temperature dependence of reactions to enable subpicosecond reactions.