title: Which step in the photolytic cycle is responsible for the visual excitation mechanism?
mesh_terms: D000200:Action Potentials; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D002417:Cattle; D004594:Electrophysiology; D008027:Light; D010786:Photoreceptor Cells / Q000033:anatomy & histology / Q000378:metabolism / Q000502:physiology*; D051381:Rats; D012168:Retinal Pigments / Q000502:physiology
chemical_list: D012168:Retinal Pigments; D000251:Adenosine Triphosphatases