The antenna complex is important, allowing the collection of light excitation energy over a larger surface area. This allows more energy to be collected, increasing the rate of proton and electron transfer.
Using Forster resonance energy transfer (FRET), it is possible to transfer the excitation energy from the light harvesting complex (which is made up of antenna chlorophyll) to the reaction centre. This elevates the turnover rate, allowing it to approach the theoretical maximum.