Hemoglobin is a protein in red blood cells that binds to oxygen. Which physiological changes that naturally occur in the body reduce hemoglobin's affinity for oxygen?

Explanation:

Hemoglobin is a biological macromolecule of protein contained in red blood cells, which efficiently carries oxygen from the lungs to other tissues of the body. Hemoglobin helps in the transportation of carbon dioxide and hydrogen ions back to the lungs.

Hemoglobin consists of four non-organic subunits, each with a cofactor called a haem group that has an iron atom center. The iron is the main component that actually binds to oxygen, thus each hemoglobin molecule is able to carry four molecules of O2. Cooperation among the four subunits of the hemoglobin molecule is necessary for the efficient transportation of O2. The four subunits of hemoglobin actually bind to oxygen cooperatively, the binding of oxygen to one site of the four subunits will increase the likelihood of the remaining sites to bind with oxygen as well.

The binding of the first oxygen allows the second, third, and fourth oxygen molecules to subsequently bind with increasing ease. Haemoglobin easily bonds with CO2 relatively faster than O2. When the carbon dioxide is in direct equilibrium with the concentration of protons in the blood, increasing blood carbon dioxide levels leads to a decrease in pH, which ultimately leads to a decrease in affinity for oxygen by hemoglobin.