Glucuronic Acid

Heme Degradation - Erythrocytes have a lifetime of about 120 days. Aged erythrocytes are destroyed upon passage through the spleen or liver (Figure 21.31). The basic pathway of heme breakdown is:

Heme -> Biliverdin -> Bilirubin -> (passage through blood to liver as bilirubin-albumin complex) -> Bilirubin diglucuronide -> excretion.

Bilirubin is insoluble in aqueous solutions, so complexing with albumin and gluruonic acid is essential for passage through the body. Accumulation of bilirubin in the blood leads to jaundice.

See also: Uronic acids, hyaluronic acid, bilirubin, UDP-Glucuronate