And the chloride shift takes place not only in the tissues but also in the lungs. But the process is reversed, as we'll see in just a moment. So let's begin by focusing on the chloride shift as it takes place inside our tissues. So, inside the cells of exercising tissues, these cells are continually undergoing different types of metabolic processes such as cellular respiration. And so the major waste byproduct that is produced in the process is carbon dioxide. Now, of course, carbon dioxide is a nonpolar molecule and so it will not readily diffuse in our blood plasma.