What is the role of hemoglobin in oxygen transport?

Hemoglobin binds to oxygen and transports it from the lungs to the body's tissues.

Hemoglobin is a protein found in red blood cells that is responsible for carrying oxygen from the lungs to the body's tissues. It consists of four subunits, each containing a heme group that can bind to one molecule of oxygen. When oxygen enters the lungs, it diffuses into the alveoli and binds to the heme groups of hemoglobin molecules in the red blood cells. This forms oxyhemoglobin, which is bright red in colour.

As the blood circulates through the body, oxyhemoglobin releases oxygen to the tissues that need it. This is due to the fact that the concentration of oxygen is lower in the tissues than in the blood. The oxygen diffuses out of the red blood cells and into the tissues, where it is used for cellular respiration to produce energy.

Once the oxygen has been released, hemoglobin binds to carbon dioxide, a waste product of cellular respiration, and transports it back to the lungs to be exhaled. This process is known as the Bohr effect, and it helps to regulate the pH of the blood.

In summary, hemoglobin plays a crucial role in oxygen transport by binding to oxygen in the lungs, releasing it to the body's tissues, and transporting carbon dioxide back to the lungs. Without hemoglobin, the body would not be able to efficiently transport oxygen to where it is needed.