Oxyhemoglobin And The Respiratory System

Running, basketball, soccer, tennis, football: five very different sports, seemingly unrelated in any way. All focus on different skills and abilities and strengthen different parts of the body. Despite their differences, they are unified under several athletic components, most notably cardiorespiratory endurance. Whether we are laying in bed asleep, sitting listening to a teacher, or walking down the hallway, the cardiovascular and respiratory systems work together to regulate oxygen and waste throughout the body. When an activity becomes strenuous for a prolonged period of time, these systems must adapt to increase the capabilities of oxygen and waste management. The main function of the respiratory system is the exchange of gases with
As seen by the equation, the reaction is affected by oxygen and H+ concentration. Exhibiting the effects described by Le Châtelier’s Principle, a high pH and PO2 will yield the greatest saturation of oxyhemoglobin, the form of hemoglobin when it is combined with oxygen. Conversely, a low pH and low PO2 will result in a low concentration of oxyhemoglobin. Therefore, a relatively high pH of about 7.4 is desired throughout most of the bloodstream to maximize carrying capacity. On the other end, in the delivery of oxygen to metabolically active tissue, a lower pH is desired. Thus the generation of acid during cellular respiration is beneficial to the unloading of oxyhemoglobin in the surrounding area. Like all previous oxygen transfers, delivery of oxygen from the blood to metabolically active tissues occurs because of partial pressure differences. The aerobic activity constantly occurring in the tissues uses the oxygen and decreases its partial pressure creating large pressure differences. The last major contributor to the transfer of oxygen is the structure of hemoglobin. The molecule is a tetrameric hemeprotein, which allows for one allosteric bonding site in each of the four monomeric parts. This means that oxygen does not bond at the active site of the protein, rather a heme group that contains a central iron ion, Fe2+ (Lefers). The advantages of hemoglobin are seen in the allosteric properties stemming from its quaternary structure, the arrangement of its subunits. As each oxygen molecule bonds to hemoglobin, the allosteric properties change hemoglobin’s structure meaning oxygen acts as a homotropic effector that increases hemoglobin’s affinity for other oxygen molecules. This gives the hemoglobin an extra push to bond with oxygen as it reaches saturation in the pulmonary capillaries. As hemoglobin releases oxygen in the active tissues, oxygen is released more readily