Final answer:
Bilirubin transforms from unconjugated to conjugated form in the liver, where it becomes water-soluble and ready for excretion through the bile duct into the intestine.
Step-by-step explanation:
Bilirubin is converted from its unconjugated to conjugated form in the liver. This process is crucial for the elimination of bilirubin from the body. Unconjugated bilirubin is bound to albumin in the bloodstream and then taken up by the liver, where it is conjugated with glucuronic acid, becoming bilirubin diglucuronide, a water-soluble form that can be excreted into the bile and eventually into the intestines for disposal. The liver is the organ responsible for this transformation, effectively detoxifying the bilirubin and making it ready for excretion. The conjugated bilirubin is then sent to the intestine through the bile ducts. While in the intestine, a majority of bilirubin is further converted into stercobilinogen, and subsequently stercobilin, which imparts the characteristic brown color to feces. Any dysfunction in this process can lead to jaundice, where bilirubin builds up in the blood and tissues, often giving a yellowish tint to the skin and eyes.