3d image of stercobilinogen skeletal formula

stercobilinogen fecal urobilinogen gut bacteria hemoglobin brown color heme bilirubin feces stercobilin rivers erythrocytes macrophages biliverdin plasma protein albumin bilirubin diglucuronide bile biliary tract metabolite metabolism biosynthesis cycle mechanism pathway path catabolism biosynthetic intermediate biogenesis substrate precursor synthesis derivative bioprecursor metabolic enzyme endogenous molecule molecular formula skeletal structural structure 3d