What component of blood carries carbon dioxide?

The component of blood that carries carbon dioxide is the red blood cell. These cells contain hemoglobin, a protein that has a high affinity for oxygen, allowing it to transport oxygen from the lungs to the tissues. However, red blood cells also play a crucial role in returning carbon dioxide, a waste product of metabolism, from the tissues back to the lungs for exhalation.

When carbon dioxide enters the bloodstream, a significant portion is transported by red blood cells. Inside these cells, carbon dioxide binds to hemoglobin to form carbaminohemoglobin. Additionally, some carbon dioxide is converted to bicarbonate ions, which are then transported in plasma, but the direct capture and transport along with oxygen occur within red blood cells. This dual role of red blood cells in gas exchange is essential for maintaining the body’s pH balance and respiratory function.

Other components such as white blood cells and platelets are not involved in gas transport, and while plasma carries dissolved gases, the primary vehicle for carbon dioxide transport in the bloodstream is indeed the red blood cell.