Question

explain how the oxygen's affinity to hemoglobin changes in your lungs. What happens to N-carbomates and to Bohr's protons all that moment? What changes take place in hemoglobin itself?

Answer 1

Bohr effect

• Hemoglobin binds oxygen more tightly at high pH than at lower pH. This phenomenon is called the Bohr effect.

Chagne of Bohr Protons at lungs

• Due to this effect, hemoglobin has the ability to pick up or donate hydrogen ions.
• When pH rises, hemoglobin loses hydrogen ions from specific amino acids at key sites in its structure, and this causes a subtle change in its structure that enhances its ability to bind oxygen.
• When pH falls, the reverse happens: hemoglobin picks up hydrogen ions and its affinity for oxygen decreases.

Oxygen Transport at lungs

When blood nearer to the lungs, the carbon dioxide concentration decreases, which increases the pH.

This increase in pH increases hemoglobin's affinity for oxygen binding through the Bohr effect. Therefore   hemoglobin picks up oxygen from the lungs and transport it to the tissues.

In the tissues, the increasing CO₂ concentration decreases the pH, which helps hemoglobin to dump the oxygen in the tissues

The pH-mediated change in affinity for oxygen helps hemoglobin act like a shuttle that picks up oxygen in the lungs and deposits it in the tissues where it will be needed

Shape of Hemoglobin when it binds with oxygen

Heme group is nonplanar when it is not bound to oxygen; the iron atom is pulled out of the plane of the porphyrin ring.

This nonplanar configuration is characteristic of the deoxygenated heme group, and it is termed as "domed" shape

When the Fe in the heme group binds to an oxygen molecule, the porphyrin ring adopts a planar configuration and hence the Fe lies in the plane of the porphyrin ring