Question

chosen - glycosylated hemoglobin

1. structure and function
2. what specific globin chains are in normal hemoglobin and in chosen hemoglobin
3. how does iron play in to hemoglobin and its molecule and transportation?
4. how does oxygen play in to hemoglobin and its molecule and transportation?

Answer 1

1. Structure and functions:

Hemoglobin is the protein that transports oxygen in our blood. All four heme groups bind to oxygen . Two amino acid side chains are covalently bound to sugar molecules  in a type of modification called glycated. This happened because the protein experienced high sugar levels for a long time. The sugar is is labeled fructose, but it originated from glucose. Glucose forms a glycosidic bond with the nitrogen atom of the sidechain of lysine. Then, it dehydrates to a Schiff base and undergoes Amadori rearrangement(a shift in the double bond) to fructose. In hemoglobin from patients with untreated diabetes, the modifications include glucose linked to the amino terminal groups of the alpha and beta chains as well as modification of lysine side chains by glucose. The HbA1c test ^[4]specifically tests for the modification of the amino terminus of the beta chain

The Diabetes Control and Complications Trial (DCCT) showed that diabetics who keep their glycosylated hemoglobin levels close to 7% have a much better chance of delaying or preventing diabetes complications that affect the eyes, kidneys, and nerves than people with levels 8% or higher. A change in treatment is almost always needed if the level is over 8%. Lowering the level of glycosylated hemoglobin by any amount improves a person's chances of staying healthy.

2.Normal hemoglobin consists of four globin chains, each holding a heme molecule that contains iron. Globin is a complex protein containing a precise sequence of amino acids that allows it to fold into a complex conformational pattern. It is variations in the globin chains that leads to the hemoglobinopathies.

3.Iron is an essential element for blood production. About 70 percent of your body's iron is found in the red blood cells of your blood called hemoglobin and in muscle cells called myoglobin. Iron in hemoglobin binds to the oxygen and thus facilitating its transport from the lungs via the arteries to all cells throughout the body.

Iron is a chemical element in the periodic table that has the symbol Fe and atomic number 26. Iron is group 8 and period 4 metal.

Transferrin is the major iron transport protein (transports iron through blood). Fe3+ is the form of iron that binds to transferrin, so the Fe2+ transported through ferroportin must be oxidized to Fe3+. Once oxidized, Fe3+ binds to transferrin and is transported to a tissue cell that contains a transferrin receptor.

4.Once oxygen has entered the blood from the lungs, it is taken up by haemoglobin (Hb) in the red blood cell.Each molecule of haemoglobin can hold four oxygenmolecules. It is haemoglobin that carries the oxygen as it is transported around the body in the blood.

Although oxygen dissolves in blood, only a small amount of oxygen is transported this way. Only 1.5 percent of oxygen in the blood is dissolved directly into the blood itself. Most oxygen, 98.5 percent, is bound to a protein called hemoglobin and carried to the tissues.