Retinylidene proteins, or rhodopsins in a broad sense, are proteins that use retinal as a chromophore for light reception. They are the molecular basis for a variety of light-sensing systems from phototaxis in flagellates to eyesight in animals. Retinylidene proteins include all forms of opsin and rhodopsin (in the broad sense).
Retinylidene proteins, or opsins broadly defined, are proteins that utilize retinal as a chromophore for light detection. They serve as the molecular foundation for diverse light-sensitive systems from phototaxis in flagellates to vision in animals. Retinylidene proteins include all forms of opsin and rhodopsin (broadly speaking).