Biochemistry of Visual Processes

摘要: Publisher Summary The initial stage of photoreception, that is, absorption incident radiations, occurs in the outer segments rods and cones. Between a quantum radiation its final splitting into retinaldehyde opsin, rhodopsin molecule passes through many intermediate stages. Some molecular species produced might be so short-lived their presence is revealed glycerol-water mixtures at low temperatures. way which visual-pigment molecules, having absorbed radiation, can initiate nervous response eye, provides fascinating problem sensory physiology. Visual pigments vision either by activating an attendant enzyme assembly or altering immediate electrical milieu. Specific carriers transfer excitation to disc perimeters, where they could produce local depolarization plasma membrane. spreading wave amplified membrane enclosing ellipsoid region inner segment, densely-packed mitochondria suggest high demand for adenosine triphosphate (ATP).