A Case of Iron Deficiency

A Case of Iron Deficiency

(Summarizing and Note-Taking)

Directions: Go to this website: http://www.sciencecases.org/ida/ida.asp and answer the following questions:

1. Describe the structure of a molecule of hemoglobin and explain the role played by iron in the transport of oxygen.

Hemoglobin is a quaternary protein composed of four polypeptide chains, each attached to a heme group, containing an iron atom. It is located in the erythrocytes of all vertebrates and transports most of the blood oxygen. Each iron atom of each heme group can bind to diatomic oxygen, leading to a favorable change in oxidation state for iron from +2 to +3. It can also deliver oxygen easily because it exhibits a relaxed state (deoxy state) that releases the oxygen, and reduces the iron atoms from +3 to +2. It is also exhibits cooperativity, such that as saturation of oxygen increases, it becomes easier for more oxygen to bind to the heme groups.

2. How is iron stored and transported in the body?

Approximately ⅔ of the iron in the body is stored in hemoglobin. The remaining that is not available directly in the blood is stored in iron-storing proteins known as ferritin. Ferritin is used as a buffer to protect the body from potential iron shortages.

3. What is Iron Deficiency Anemia (IDA) and how frequently does it occur?

Iron deficiency anemia is the most common form of anemia that arises when there is not enough iron present in the body to produce hemoglobin, making the red blood cells smaller, and thereby insufficient in transporting oxygen. It is estimated that over one billion people exhibit iron deficiency.

4. What are the most common causes of IDA?

Possible causes of iron deficiency include deficient diet (of iron), decreased absorption, increased requirements due to pregnancy or lactation, or different types of blood loss. Such blood loss can be gastrointestinal, menstrual, or via blood donation.

5. Why are women more prone to IDA...