Oxygen Dissociation Curves

Quaternary protein

A protein composed of multiple polypeptide chains.

Haemoglobin function

Each haemoglobin can carry 4 oxygen molecules, equivalent to 8 oxygen atoms.

How is the creation of oxyhaemoglobin a reversible reaction

The reaction between haemoglobin and oxygen can reverse, allowing oxygen release at respiring tissues.

Partial pressure of a gas

The pressure produced individually by a gas in a system.

Haemoglobin's affinity for oxygen

Depends on the partial pressure of oxygen (pO2).

Oxygen dissociation curve

A graph showing how saturated with oxygen the haemoglobin is at any given pO2.

S-shaped curve

The shape of the oxygen dissociation curve due to changes in haemoglobin's structure as oxygen binds.

High partial pressure of oxygen

Conditions where haemoglobin’s affinity for oxygen is high and facilitates the loading of oxygen.

Low partial pressure of oxygen

Conditions where haemoglobin's affinity for oxygen is low, leading to oxygen unloading.

Loading process

The binding of oxygen to haemoglobin that occurs in high oxygen partial pressure environments like the lungs.

Unloading process

The release of oxygen from haemoglobin that occurs in low oxygen partial pressure environments like respiring tissue.