Only about 5% of the carbon dioxide will exist in the blood plasma in its CO2 form. About 90% of the carbon dioxide, as we'll see in just a moment, actually exist in its bicarbonate ion form. Now, how exactly do we transform the carbon dioxide into its soluble bicarbonate ion form? So basically, inside the cells of our tissue, different types of processes produce a bunch of carbon dioxide molecules. And because these molecules are non polar, they can easily diffuse across the membrane of the cells of the tissue and enter the extracellular matrix. And then they diffuse across the capillary walls found nearby our tissue cells.