Hemoglobin is involved in the transport of other gases: It carries some of the body's respiratory carbon dioxide<span> (about 20–25% of the total</span><span>) as </span>carbaminohemoglobin<span>, in which </span><span>CO2</span><span> is bound to the globin protein. The molecule also carries the important regulatory molecule </span>nitric oxide<span> bound to a globin protein </span>thiol<span> group, releasing it at the same time as oxygen.</span>
