The difference between hemoglobin and plasma protein: First, the location of the two proteins is different, hemoglobin exists in red blood cells, and plasma protein exists in the blood plasma. The composition of hemoglobin and plasma protein is different, hemoglobin is composed of bead protein and hemoglobin, and plasma protein is composed of albumin and globulin. Third, the functions of the two proteins are different. Hemoglobin exists in red blood cells and its main function is to transport oxygen and carbon dioxide, hemoglobin can combine with oxygen to form oxygenated hemoglobin and with carbon dioxide to form carboxyhemoglobin, which plays a transport role. The albumin of plasma protein is the protein of the body to maintain the colloid osmotic pressure and nutritional status, and plasma globulin is mainly composed of various antibodies and has immune function.