Well, because we have a smaller positive charge the two three BPG will not be able to bind as strongly to that center pocket as it binds in the normal hemoglobin. And so what that means is the fetal hemoglobin will not bind the two three BPGS strongly. And so because of that, the fetal hemoglobin will have a higher affinity for oxygen than the normal hemoglobin found inside the blood of the mother. And what that means is the fetal hemoglobin will be much more attractive to the oxygen. And that's important because it needs to be able to effectively and efficiently take the oxygen from the mother's blood and deliver it into the blood system of that developing fetus. Now, if we examine the oxygen binding curve we see that this green curve basically describes the oxygen binding curve for the fetal hemoglobin while the blue curve describes the oxygen binding curve for the hemoglobin found in the mother's blood, the normal hemoglobin.