Question

The heme within macrophages that have consumed RBCs is further broken down into iron and protoporphyrin. What is the process by which heme is broken down?

1) Oxidation
2) Reduction
3) Hydrolysis
4) Decarboxylation

Answer 1

Heme is broken down into iron and protoporphyrin within macrophages that have consumed RBCs. The non-iron portion of heme is degraded into biliverdin and then into bilirubin. Bilirubin is used in the manufacture of bile and eliminated from the body in the feces.

Step-by-step explanation:

In the process of heme breakdown, the heme within macrophages that have consumed RBCs is further broken down into iron and protoporphyrin. This process involves a series of reactions:

1. The non-iron portion of heme is degraded into biliverdin, a green pigment, and then into bilirubin, a yellow pigment.
2. Bilirubin binds to albumin and travels in the blood to the liver.
3. In the liver, bilirubin is used in the manufacture of bile, a compound released into the intestines to help emulsify dietary fats.
4. In the large intestine, bacteria break down bilirubin into urobilinogen and then into stercobilin, which is eliminated from the body in the feces.