Iron hemoglobin

In the blood, 2.5-3.0 g of hemoglobin iron circulates as a component of the erythrocytes (top right). Over the course of several months, the flexibility of the red blood cells constantly declines due to damage to the membrane and cytoskeleton. Old erythrocytes of this type are taken up by macrophages in the spleen and other organs and broken down. The organic part of the heme is oxidized into bilirubin (see p. 194), while the iron returns to the plasma pool. The quantity of heme iron recycled per day is much larger than the amount resorbed by the intestines. 

Probably the most intriguing and important properties of transferrin are those involved in its physiological role as the source of iron for the biosynthesis of hemoglobin by the immature red blood cell. About 30 mg of iron are incorporated into hemoglobin synthesized by the normal adult bone marrow each day, or about 10 times the amount of non-hemoglobin iron in the circulation at any time. Transferrin is the shuttle for this traffic. Since the half-life in serum iron bound to transferrin is 1-2 hr while the half-life of the protein is about 7-8 days (51), the protein must be conserved during its interaction with the immature red cell and re-... 

Transport and storage. Many small molecules and ions are transported in the blood and within cells by being bound to carrier proteins. The best example is the oxygen-carrying protein hemoglobin. Iron is stored in various tissues by the protein ferritin. 

Iron is used to regenerate hemoglobin. Iron is absorbed in the intestine and enters plasma as heme. Iron is stored as ferritin in the liver, spleen, and bone marrow. Five to twenty milligrams of iron are required daily. Iron deficiency causes anemia. Iron is found in liver, lean meats, egg yolks, dried beans, green vegetables (i.e., spinach), and fruit. Women who are pregnant should increase their iron intake as specified by the healthcare provider. Large doses of iron are prescribed in the second and third trimesters. The patient must adhere to the... 

Hp is a natural bacteriostatic agent in infection with iron-requiring bacteria, such as Escherichia coU, probably by preventing the use of hemoglobin iron by these organisms. 

Hemoglobin, Iron, and Bilirubin Hemoglobin, Iron, and Bilirubin Appendix... 

Relative Biological Value calculated by dividing the efficiency of converting iron from the test diets into hemoglobin iron relative to that for diets containing ferrous. sulfate. 

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