retinal, molecular structures, polyene chromophore, 3d model, structural chemical formula and atoms with color coding

retinal molecular structure chemical formula model c20h28o aldehyde polyene chromophore atom carbon oxygen hydrogen bond molecule visual health care vision research study biochemistry chemistry drug biology science disease eye composition material medicine essential retina atomic skeletal substance vitamin metabolism chain supplement illustration nutrient compound organic biomolecule retinaldehyde retinene structures structural atoms color coding coding