<prompt> True regarding unconjugated bilirubin is -Not lipid solubleMore water solubleExcreted by kidney easilyBound with serum albumin  <response>: Unconjugated bilirubin Unconjugated bilirubin is highly lipid soluble lipophilic.It is insoluble in water and tightly bound to albumin cannot be excreted in urine.Unbound fraction, which is increased in hemolytic reactions e.g. erythroblastosis fetalis, can cross blood-brain barrier because of lipophilic nature and can cause brain damage of newborn Kernicterus.Conjugated bilirubinConjugated bilirubin is water soluble and only loosely bound to albumin and thus is easily filtered by glomeruli and excreted in urine. 