Answer:
Reaction center is a complex made up of the proteins and the photosynthetic pigment like pheophytin and chlorophyll.
The reaction center components are arranged in a way that they can capture the energy from the photons of the light energy which can excite the electrons of the chlorophyll molecule.
The reaction center helps convert the light energy to the chemical energy in the form of ATP and NADPH utilized in the synthesis of the sucrose molecule.
Since reaction center response in the presence of light, therefore is considered a part of the light-dependent phase of photosynthesis.