Hemoglobin Structure and Function

Red blood cells are the key to life. They are constantly traveling through your body, delivering oxygen and removing waste. If they didn’t do their job, you would slowly die. Red blood cells contain a protein called hemoglobin that gives blood its red hue. Hemoglobin contains iron, which makes it an excellent vehicle for transporting oxygen and carbon dioxide. As blood passes through the lungs, oxygen molecules attach to the hemoglobin. When the blood passes through the body’s tissue, the hemoglobin releases oxygen to the cells. The empty hemoglobin molecules then bond with the tissue’s carbon dioxide or other waste gasses to transport them away. Over time, red blood cells get worn out and eventually die. The average life cycle of a red blood cell is only 120 days. But don’t worry! Your bones are continually producing new blood cells. Hemoglobin Facts and Stats: Each red blood cell (RBC) contains about 280 million Hb molecules. The average adult contains about 5 billion RBCs/milliliter of blood. The average adult has about 5 liters of blood. Thus, the average adult has about 790 grams (or pounds) of Hb. Assuming the blood re-circulation time at rest is about 1 minute, the net transport of oxygen by Hb is about 0.1 liter/minute (or mole/minute). Key words: 1. The number of protein chains in each hemoglobin molecule is 2. The number of heme-iron complexes in each hemoglobin molecule is 3. When saturated, the number of oxygen atoms bound by one molecule of hemoglobin is #hemoglobin #polypeptide #protein #heme #oxygen #RBC #redBloodCells