Actually, that's not correct. The reaction centers in chloroplasts absorb two photons, at 680 and 720 nanometers. This is used to reduce water, shunt protons across a membrane, and reduce NADP+. The protons go on to produce ATP, and the NADPH drives the Kreb's cycle, which produces sugars, which can be oxidized to produce ATP. But it's a far, far way from being a 100% effecient system.