Now, if hemoglobin can bind more of these oxygen molecules, why do we need myoglobin molecules in the first place? And in general, why does our body need to use two different proteins to carry out the same function of bringing the oxygen to the cell? Well, as it turns out, because these two proteins have slightly different structures, they have slightly different properties and therefore slightly different functions. As we'll see in just a moment, myoglobin is used to store the oxygen, while the hemoglobin is actually used to bring the oxygen continually from the lungs and to the tissues of our body. And we'll see exactly why that is. So in just a moment.