Question

If protoporphyrin is deficient (e.g. sideroblastic anemia), what happens to the iron?

1) It remains trapped in the mitochondria
2) It is released into the bloodstream
3) It is excreted from the body
4) It is converted into heme

Answer 1

In the case of a protoporphyrin deficiency, such as sideroblastic anemia, iron cannot be utilized for heme synthesis and becomes trapped in the mitochondria within erythroblast cells.

Step-by-step explanation:

If protoporphyrin is deficient, as in the case of sideroblastic anemia, the iron remains unable to be utilized for heme synthesis. As a result, iron does not form heme and gets trapped in mitochondria within erythroblast cells. This trapped iron appears as ringed sideroblasts when visualized under a microscope. The surplus iron may accumulate in the mitochondria and eventually be stored in the liver as hemosiderin. It's important to note that the iron is not efficiently released into the bloodstream, excreted from the body, or converted into heme when there is a protoporphyrin deficiency because the synthesis of heme is disrupted.