This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Proteins and Amino Acids, Subject name: Biochemistry
The conjugation of bilirubin to glucuronic acid in the liver; 
Select and explain. 
A. Converts a hydrophilic compound to a hydrophobic one, B. Converts a hydrophobic compound to a hydrophilic one, C. Enables the bilirubin molecule to cross the cell membrane, D. Is increased during neonatal jaundice
B: Converts a hydrophobic compound to a hydrophilic one
Answer: B: Converts a hydrophobic compound to a hydrophilic one 
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