Now, when we produce an excess amount of two three BPG, some of these molecules leave the cell and enter our matrix. Now, what exactly does a two three BPG molecule actually look like? Well, it looks something like this. So we have one two three carbons, and we also have these two phosphate groups. And as we'll see in just a moment, these two phosphate groups, because they have a negative charge, they play a crucial role in actually binding to our deoxyhemoglobin molecules. So once our two three BPG molecules into the matrix, they're then diffused via the capillary wall and into the blood plasma found inside the capillary.