Question

............. and ............. pigments are formed by the decomposition of haemoglobin in the liver.

Answer 1

Hemoglobin is a protein, but one that has a prosthetic group (non-protein functional component) called heme. When red blood cells die, the hemoglobin is broken down and partially reused. The protein component is just broken down to individual amino acids so they can be recycled into newly synthesized proteins or other metabolites. A lifetime of RBC is 120 days. Hemoglobin breaks down into globin (protein part) and heme. The heme initially breaks apart into biliverdin, a green pigment which is rapidly reduced to bilirubin, orange-yellow pigment. This process takes place in the liver, spleen.