Rutgers Anatomy & Physiology II Practice Exam

Most carbon dioxide is transported in the blood primarily as a bicarbonate ion. This process occurs when carbon dioxide enters red blood cells, where it is quickly converted into carbonic acid through the reaction with water, catalyzed by the enzyme carbonic anhydrase. This carbonic acid then dissociates into bicarbonate and hydrogen ions. The bicarbonate ion then diffuses into the plasma, making it the most significant form of carbon dioxide transportation in the bloodstream.

This mechanism plays a vital role in maintaining acid-base balance in the body. The production of bicarbonate also helps to regulate pH levels, as it can combine with excess hydrogen ions to form carbonic acid when the blood becomes too acidic. Thus, understanding this transport method is crucial for comprehending how the body manages carbon dioxide waste and maintains homeostasis.