Bilirubin, the molecule responsible for the yellowish color of bruises, is formed from the hydrogenation of a double bond in biliverdin, which is a product of heme degradation (heme is an iron-contain...Bilirubin, the molecule responsible for the yellowish color of bruises, is formed from the hydrogenation of a double bond in biliverdin, which is a product of heme degradation (heme is an iron-containing coenzyme in the oxygen-carrying blood protein hemoglobin).
