What is the Bohr effect?
The correct answer and explanation is :
The Bohr effect is a physiological phenomenon where an increase in carbon dioxide (CO₂) concentration or a decrease in pH (more acidic conditions) reduces hemoglobin’s affinity for oxygen, promoting oxygen release to tissues. Conversely, a decrease in CO₂ or an increase in pH enhances hemoglobin’s oxygen-binding capacity.
Detailed Explanation (300 words)
The Bohr effect, first described by the Danish physiologist Christian Bohr in 1904, plays a crucial role in oxygen transport and delivery in the body. Hemoglobin, the oxygen-carrying protein in red blood cells, binds oxygen in the lungs and releases it in tissues where it is needed.
In areas of high metabolic activity, such as muscle tissues, cells produce large amounts of CO₂ as a byproduct of cellular respiration. This CO₂ dissolves in blood plasma, forming carbonic acid (H₂CO₃), which then dissociates into hydrogen ions (H⁺) and bicarbonate (HCO₃⁻). The increase in H⁺ concentration lowers the blood pH (making it more acidic). The acidic environment causes hemoglobin to undergo a conformational change that reduces its affinity for oxygen, thus releasing more oxygen to the active tissues that need it.
In contrast, in the lungs, where CO₂ levels are lower, the blood pH is relatively higher (more alkaline). This promotes oxygen binding to hemoglobin, allowing efficient oxygen uptake for transport throughout the body.
This process is critical for efficient oxygen delivery during exercise, as active muscles require more oxygen and produce more CO₂. The Bohr effect enhances oxygen unloading in these areas, ensuring proper tissue oxygenation.
Overall, the Bohr effect is an essential physiological adaptation that helps maintain oxygen homeostasis, enabling our body to respond dynamically to varying metabolic demands.
