Upon light absorption by photosynthetic pigments in light-harvesting antenna proteins, Coulombically bound electron-hole pairs called excitons are created. Excitons hop from the site of creation to the reaction center in the light-harvesting antenna network. The process of exciton hopping along the antenna pigment network is near-unity efficient. This thesis reports the observation of photosynthetic design strategies that enable the high transfer efficiency of excitons in photosynthesis. In Chapter 2, I demonstrate adaptation of the spatial patterns of the arrangements of proteins on the photosynthetic membrane towards maximum efficiency in different light fluences. I show that reaction center clustering is favored in high light fluences to maximize exciton trapping. In Chapters 3 and 4, I have described mechanisms for effective energy capture through chromophore-protein interactions in the cyanobacterial light-harvesting antenna, phycobilisome. In Chapter 4, I show that single-residue level hydrogen-bonding interactions with phycobilisome chromophores prevent excited-state relaxation that hampers energy transfer. In Chapter 4, I also observe that environmental vibrations are tuned to enhance directional downhill energy transfer through the antenna. In Chapter 3, I observe that the energetic landscape of the antenna is tuned through quaternary-level chromophore-protein interactions to create directional energy flow. In Chapter 5, I observe chiral regulation of energy transfer in the LH2 antenna of purple bacteria. I observe that right-handed exciton states in the antenna transfer energy faster than left-handed states. The findings in these chapters describe how coupling to the environment is tuned in photosynthesis to regulate energy release to the environment and to create unidirectional exciton flow.