Which enzyme is responsible for the conjugation of bilirubin?

The enzyme responsible for the conjugation of bilirubin is UDP-glucuronyl transferase. This enzyme plays a crucial role in transforming unconjugated bilirubin, which is lipid-soluble and not easily excreted, into conjugated bilirubin that is water-soluble. This transformation involves the addition of glucuronic acid to bilirubin, allowing it to be excreted from the liver into the bile and subsequently eliminated from the body.

In the context of bilirubin metabolism, proper conjugation is essential for detoxifying and facilitating the elimination of bilirubin. If this process is impaired, it can lead to an accumulation of unconjugated bilirubin, resulting in conditions such as jaundice.

Other enzymes listed do not participate in the bilirubin conjugation process. Hexokinase is involved in glucose metabolism and the glycolytic pathway. Glucose-6-phosphate dehydrogenase plays a key role in the pentose phosphate pathway and in managing oxidative stress within cells. Alkaline phosphatase is mainly associated with dephosphorylation processes and is not directly involved in bilirubin conjugation.