Identify the correct statements regarding the Bohr effect in

Identify the correct statements regarding the Bohr effect in hemoglobin. The fractional O_2 saturation curve shifts to the right as pH decreases H+ stabilizes the low affinity state of Hb O2 release is favored in respiring tissues A and C All of the above

Solution

Answer – all the above are right

The Bohr effect increases the efficiency of oxygen transportation through the blood. After hemoglobin binds to oxygen in the lungs due to the high oxygen concentrations, the Bohr effect facilitates its release in the tissues, particularly those tissues in most need of oxygen. When a tissue\'s metabolic rate increases, so does its carbon dioxide waste production.

A decrease in pH (increase in H+ ion concentration) shifts the standard curve to the right, while an increase shifts it to the left. This occurs because at greater H+ ion concentration, various amino acid residues, such as Histidine 146 exist predominantly in their protonated form allowing them to form ion pairs that stabilize deoxyhemoglobin in the T state. The T state has a lower affinity for oxygen than the R state, so with increased acidity, the hemoglobin binds less O2 for a given PO2 (and more H+). This is known as the Bohr effect.A reduction in the total binding capacity of hemoglobin to oxygen (i.e. shifting the curve down, not just to the right) due to reduced pH is called the root effect. This is seen in bony fish. The binding affinity of hemoglobin to O2 is greatest under a relatively high pH.