Hemoglobin

Hemoglobin is a protein in red blood cells that carries oxygen from the lungs to the rest of the body and returns carbon dioxide back to the lungs for exhalation. It consists of four subunits, each containing iron, which binds to oxygen, giving blood its red color. Hemoglobin is essential for life, as it ensures that organs and tissues receive the oxygen they need to function properly. Additionally, it helps regulate blood pH and plays a role in transporting various gases in the blood, making it a crucial component of our circulatory system.