retinal molecular structure, 3d model molecule, retinaldehyde, structural chemical formula view from a microscope

retinal retinaldehyde polyene chromophore chemical basis of visual phototransduction form vitamin molecule molecular structure formula 3d model c20h28o atom chemistry science biochemistry research vision health compound organic eye supplement nutrient aldehyde biomolecule atomic metabolism skeletal biology bond care medicine substance composition drug food carbon disease oxygen study essential hydrogen chain