What is the main function of hemoglobin in red blood cells?

The main function of hemoglobin in red blood cells is acquiring oxygen. Hemoglobin is a protein molecule located in red blood cells that has a strong affinity for oxygen. When red blood cells pass through the lungs, hemoglobin binds to oxygen molecules, allowing the cells to carry oxygen from the lungs to the tissues and organs throughout the body. This process is crucial for cellular respiration, where cells utilize oxygen to produce energy.

Additionally, while hemoglobin plays a role in transporting carbon dioxide back to the lungs for exhalation, its primary role is oxygen transport. It is this ability to bind oxygen that makes hemoglobin essential for sustaining life, as the body's cells depend on a continuous supply of oxygen to function properly.