Principles of Biochemistry, Volume 2 - A. Lehninger 1985

Bioenergetics and Metabolism
Biosynthesis of Amino Acids and Nucleotides
Bile pigments are formed as a result of the breakdown of heme groups

The iron-porphyrin group, or heme group, of Hemoglobin released from erythrocytes degraded in the Spleen is broken down to yield free Fe3+ and ultimately bilirubin, an open-chain tetrapyrrole derivative (Fig. 22-13). Bilirubin binds to Blood serum albumin and is transported to the Liver, where it is converted into a Water-soluble derivative that is excreted into the Bile. Bilirubin is the pigment responsible for the yellow discoloration of the Skin and the whites of the eyes in jaundice, which develops As a result of impaired liver function. Determining the concentration of bilirubin in the blood serves as a diagnostic tool for this condition and other liver diseases.

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Fig. 22-13. Bilirubin is one of the bile pigments. It is formed by the Cleavage of the tetrapyrrole (porphyrin) ring of the heme group and its conversion into the linear Structure shown here. Determining blood bilirubin concentration serves as a diagnostic method for certain liver diseases.



Last update: 06/08/2026

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