Question

No matter how much oxygen is extracted from the blood even under conditions like long
marathon race, or high amount of CO2 produced at tissue levels, how the PO2 and PCO2 of
human systemic arterial blood leaving the lungs remains within normal range of their
respective values?​

Answer 1

Answer:

Oxygen (O2) competitively and reversibly binds to hemoglobin, with certain changes within the environment altering the affinity in which this relationship occurs. The sigmoidal shape of the oxygen dissociation curve illustrates hemoglobin’s propensity for positive cooperativity, as hemoglobin undergoes conformational changes to increase its affinity for oxygen as molecules progressively bind to each of its four available binding sites. The Bohr effect describes hemoglobin’s lower affinity for oxygen secondary to increases in the partial pressure of carbon dioxide and/or decreased blood pH. This lower affinity, in turn, enhances the unloading of oxygen into tissues to meet the oxygen demand of the tissue

Explanation:

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