Question

What effects might you expect in a mammal whose major hemoglobin is mutated such that it lacks a Bohr effect? Include an oxygen dissociation curve and a description of the Bohr effect in the answer

Answer 1

Answer)

Bohr effect -

The effect of partial pressure of carbondioxide and hydrogen ion concentration on the oxygen affinity of hemoglobin is called bohr effect.

Increase in carbondioxide causes increase in partial pressure of carbondioxide and increase in hydrogen ion concentration causes decrease in pH. These conditions result in the reduction of the affinity of hemoglobin for oxygen.

Bohr effect is loading of carbondioxide to blood causes unloading of oxygen i.e hemoglobin binds to carbondioxide by dissociating from oxygen forming deoxyhemoglobin.

This phenomenon is seen at tissue level, where carbondioxide levels are high.

Oxygen-hemoglobin dissociation curve explains the relation between saturation of hemoglobin and partial pressure of oxygen.

This curve shifts to right, when there is high affinity of hemoglobin for carbondioxide.

This curve shifts to left, when there is high affinity of hemoglobin for oxygen.

Oxygen-hemoglobin dissociation curve shifts to right in bohr effect.

Mutation in hemoglobin such it lacks a bohr effect -

As there is no bohr effect, the affinity of hemoglobin for oxygen increases, so that hemoglobin is more saturated and affinity for carbondioxide decreases.

As affinity of hemoglobin for oxygen increases, more hemoglobin binds to oxygen causing less release of oxygen to the tissues.

Less delivery or release of oxygen to tissues leads to hypoxia (lack of enough oxygen) of tissues, so that tissues cannot function properly and may die.

The oxygen-hemoglobin dissociation curve shifts to left in this condition.