Bile pigments are responsible for which property of bile?

• A. Osmolarity
• B. Color
• C. pH
• D. Viscosity

Answer: (B)

Bile pigments, mainly bilirubin, determine the color of bile. Bilirubin comes from the breakdown of heme and is excreted into bile after liver processing, where bilirubin and its pigment products give bile its characteristic yellow-green hue. Other properties like osmolarity, pH, and viscosity are influenced by different components in bile—solutes and bile salts set osmolarity, bicarbonate-rich fluid sets pH, and cholesterol, mucus, and related substances influence viscosity. So the color of bile is a direct result of the pigment bilirubin rather than its osmolarity, pH, or viscosity.