So we have these non polar carbon dioxide molecules. And because these carbon dioxide molecules are non polar, they don't have any charge. They can easily move across the cell membrane of the cell. So the carbon dioxide molecules make their way across the cell membrane into the space and then they make their way across the endothelium and into the blood plasma. Now, once they're inside the blood plasma, what happens to the carbon dioxide molecules? Well, carbon dioxide molecules are non polar.