Question

How does increased $ pC{{O}_{2}} $ affect the release of oxygen?

Answer 1

Hint: Oxygen forms a complex with haemoglobin called the oxyhaemoglobin. This is how oxygen travels in blood. The levels $ C{{O}_{2}} $ affect the saturation of oxygen. Also, it determines the dissociation of oxyhaemoglobin at the tissue level.

Complete answer:
 $ pC{{O}_{2}} $ is the partial pressure of $ C{{O}_{2}} $ and is directly proportional to the dissociation of oxyhaemoglobin.
The partial pressure of $ C{{O}_{2}} $ and $ {{O}_{2}} $ are responsible for the intake of oxygen between the blood and tissues. Also, it affects the formation of the oxyhaemoglobin complex. Their levels lead to the exchange of $ {{O}_{2}} $ and $ C{{O}_{2}} $ by diffusion based on the concentration gradient of both the gases.
A concentration gradient of $ pC{{O}_{2}} $ works for the diffusion of $ C{{O}_{2}} $ from the tissues to the blood and from the blood to the alveoli in lungs. It is the opposite of the diffusion occurring for $ {{O}_{2}} $ . Carbon-di-oxide is 20-25 times more soluble in the blood as compared to oxygen. So, the partial pressure of $ C{{O}_{2}} $ increases the diffusion of carbon-do-oxide through the diffusion membrane.
Partial pressure $ C{{O}_{2}} $ also affects the pH of the blood. When the pH of the blood decreases it results in the liberation of oxygen. The pH of blood is altered when water reacts with carbon-di-oxide to form carbonic acid. So the pH decreases which gradually increases the $ pC{{O}_{2}} $ . The increase in $ pC{{O}_{2}} $ is the reason for the release of oxygen from the oxyhaemoglobin complex in the tissues. Similarly the decrease in $ pC{{O}_{2}} $ results in an increase in pH of blood, which incites haemoglobin to gather more oxygen.

Note:
In the lungs, high $ p{{O}_{2}} $ and low $ pC{{O}_{2}} $ leads to the formation of haemoglobin and increases intake of oxygen at the alveoli. Simultaneously, low $ p{{O}_{2}} $ and high $ pC{{O}_{2}} $ results in the dissociation of the oxyhaemoglobin at the tissues. The affinity of haemoglobin is altered by $ pC{{O}_{2}} $ .