What is hemoglobin's primary function?

Hemoglobin's primary function is to transport oxygen from the lungs to tissues throughout the body. This protein is found in red blood cells and has a high affinity for oxygen, allowing it to bind oxygen molecules in the lungs where oxygen concentration is high. Once in the tissues, hemoglobin releases the oxygen, which is vital for cellular respiration and energy production within the cells. This transport function is crucial for maintaining the oxygen supply necessary for the metabolic processes that support life.

While other options like nutrient transport and immune response are important bodily functions, they do not pertain to hemoglobin's role. Nutrients are primarily transported by other molecules like plasma proteins, while immune responses involve the action of different types of cells and proteins in the immune system, such as antibodies and white blood cells. Regulation of body temperature is primarily performed through mechanisms that involve the skin, blood circulation, and various other systems rather than hemoglobin. Thus, the focus on hemoglobin's role in oxygen transport underscores its critical importance in respiratory physiology and overall health.