title: Is proton transfer the initial photochemical process in vision?
mesh_terms: D010777:Photochemistry; D011522:Protons; D012172:Retinaldehyde / Q000031:analogs & derivatives*; D012243:Rhodopsin; D013057:Spectrum Analysis; D014785:Vision, Ocular; D014801:Vitamin A / Q000031:analogs & derivatives*
chemical_list: D011522:Protons; D014801:Vitamin A; D012243:Rhodopsin; D012172:Retinaldehyde