The absorbed light energy excites chlorophyll a molecules , causing them to emit high - energy electrons that pass down an electron - transport chain , releasing energy to synthesize atp ( photophosphorylation ) and nadph 吸收的光能可激发叶绿素a产生高能电子，经电子传递链传递后，释放能量合成atp （光合磷酸化）和nadph 。
