Photosynthetic reaction center differ from the chlorophyll molecules in the antenna complex by the presence and absence of core pigment and accessory pigment.
Explanation:
Photosynthetic reaction center contain core pigment known as chlorophyll A which can aborb wavelength of sunlight not more than 700 nm in case of Photosystem 1 and the core chlorophyll pigment of Photosystem 2 absorb light having wavelength of 680nm or less than that.
Antenna complex or light harvesting complex such as chlorophyll b,Carotenoid,Xanthophyll absorb light energy from sunlight and transfer that light energy to photosynthetic reaction center by resonance energy transfer so that the photosynthetic reaction center uses the same(light energy) in form of chemical energy to out the further reactions of photosynthesis.