The conjugation of bilirubin to glucuronic acid in the liver;
High-Yield Explanation
Ans. is 'b' i.e. converts a hydrophobic compound to a hydrophilic one.Ref: Harrison 16th/e p 239 (15th/e p 255)Bilirubin is produced in the reticuloendothelial cells of spleen and liver. This unconjugated bilirubin is not soluble in water so is bound to albumin for its transfer in plasma.Liver uptakes this unconjugated bilirubin and conjugates it with glucuronic acid generating bilirubin glucuronide which is water soluble.For more on this topic see Question no. 12 Nov. 1999