Question

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

Answer 1

Hint: An erythrocyte or red blood corpuscles appears yellow when seen singly but these appear red when in bulk due to the presence of an iron containing pigment called hemoglobin. Haemoglobin carries about 97-99 percent of oxygen from the lungs to the body tissues as oxyhaemoglobin.

Complete answer:
Haemoglobin is a conjugated protein. It consists of a basic protein called globin joined to a non-protein group called heme, hence the name haemoglobin. Heme is an iron-porphyrin ring.
The haemoglobin molecule in a mammal is formed of four heme molecules joined with four globin molecules.
The process of formation of red blood corpuscles is known as erythropoiesis and it occurs in the liver and spleen in the foetus and in the red bone marrow after birth. Protein and iron are components of hemoglobin, and vitamin and folic acid stimulate erythropoiesis. Excess RBCs are stored in the liver.
Human red blood cells are functional in the blood for only about 120 days. The worn out RBCs are destroyed in the blood itself and in the spleen and liver in particular by the process of phagocytosis. The iron in the pigment returns to the red bone marrow and is reused in the synthesis of fresh haemoglobin. Their pigment is degraded to yellowish pigment bilirubin and biliverdin which is excreted in bile. The pigment bilirubin is mainly responsible for the pale yellow colour to the blood plasma.
Hence, Bilirubin and biliverdin pigments are formed by the decomposition of haemoglobin in the liver.

Note:
If bilirubin is not excreted fully, the skin and the mucous membrane of the person becomes yellowish and this disorder is called jaundice.
Red blood cells are hemolyzed at the rate of about 2.5 million per second but are also formed at the same rate