Author Question: A congenital deficiency of transferrin results in: a. Severe anemia b. Reduced absorption of ... (Read 114 times)

shenderson6 · **on:** Jun 25, 2018

A congenital deficiency of transferrin results in:

a. Severe anemia
b. Reduced absorption of iron
c. Increased excretion of iron
d. Decreased storage of iron in organs

Question 2

Heme is composed of iron and:

a. Globin chains
b. Oxygen
c. Methemoglobin
d. Protoporphyrin IX

flexer1n1 · **Reply #1 on:** Jun 25, 2018

Answer to Question 1

ANS: A
Transferrin is the carrier protein for iron. If it is deficient, then iron cannot be effectively transported to developing RBCs (or storage), and a severe iron deficient anemia develops. When transferrin is deficient or absent, iron is absorbed through the intestine and stored in the liver, pancreas, and spleen, but very little gets to the bone marrow.

Answer to Question 2

ANS: D
Iron is incorporated into protoporphyrin IX in the mitochondria of a developing red blood cell (RBC) to form heme. Oxygen binds reversibly to the iron in heme provided that iron is in the ferrous (divalent, reduced) state. Globin chains are part of the hemoglobin molecule; four of them exist per molecule, each containing a heme group. Methemoglobin is hemoglobin in which the iron is oxidized to the ferric (trivalent) form; it cannot bind oxygen.