AP BIOLOGY

Detailed explanation-1: -Bile pigments are formed in the liver by the breakdown of haemoglobin in dead RBCs. The liver is well known to metabolize many compounds and toxins, thereby eliminating them from the body. A substantial number of these compounds are reabsorbed in the small intestine and ultimately eliminated by the kidney.

Detailed explanation-2: -The bile pigments are formed by decomposition of the porphyrin ring and contain a chain of four pyrrole rings. Bilirubin, for example, the brownish yellow pigment that gives feces its characteristic colour, is the end product of the breakdown of heme from destroyed red blood cells.

Detailed explanation-3: -Bilirubin, which is reddish-orange in colour, is the major bile pigment produced by breakdown of either haemoglobin or myoglobin in the reticuloendothelial system.

Detailed explanation-4: -Hemoglobin is broken down into heme, which is converted to biliverdin, and finally into unconjugated bilirubin (which is not water-soluble). In the bloodstream, unconjugated bilirubin binds with serum proteins-most commonly albumin. The unconjugated bilirubin is then taken up by the liver.

Detailed explanation-5: -Bile pigments are formed during the decomposition of haemoglobin, mainly in the spleen and liver.