Canadian Society for Medical Laboratory Science (CSMLS) Practice Exam

What is the function of hemoglobin in red blood cells?

1. Transporting glucose

2. Carrying carbon dioxide

3. Transporting oxygen

4. Immune defense

The correct answer is: Transporting oxygen

Hemoglobin plays a crucial role in the physiology of red blood cells by transporting oxygen from the lungs to the tissues and organs throughout the body. This iron-containing protein binds oxygen molecules in the lungs, where oxygen concentration is high, and releases them in areas where the concentration is lower, such as in body tissues that require oxygen for cellular respiration and energy production. The structure of hemoglobin allows it to efficiently pick up and release oxygen, making it indispensable for maintaining the body’s metabolic processes. While it's true that hemoglobin can also carry carbon dioxide, its primary and most well-known function is the transport of oxygen. Other options, such as transporting glucose or immune defense, do not relate to hemoglobin's role in red blood cells, as glucose transport is primarily facilitated by different mechanisms and proteins, and immune defense is largely managed by white blood cells and antibodies rather than by hemoglobin.