1. Oxygen transport by the blood involves oxygen flowing from the alveoli to the tissues via hemoglobin in the blood. The oxygen carrying capacity of hemoglobin is increased about 70 times compared to dissolved oxygen alone. 2. The oxygen-hemoglobin dissociation curve shows the relationship between oxygen pressure and hemoglobin saturation. It is sigmoid shaped due to cooperative binding of oxygen. 3. Factors like acidosis, increased temperature, and 2,3-DPG can shift the curve rightward, increasing oxygen unloading to tissues. Fetal hemoglobin and alkalosis shift the curve leftward, decreasing oxygen unloading.