Question

What is the effect on \[pC{O_2}\] oxygen transport?

Answer 1

Hint: The transportation of oxygen in blood mainly occurs in bound form as oxy-haemoglobin and in dissolved form in plasma or intracellular fluid. This transportation is very crucial and necessary for the body cells to perform their respective functions. Oxygen transport can be affected by the acidity and concentration of carbon dioxide in blood. Let us try to know a little more about it.

Complete answer:
So as mentioned above, transportation of oxygen is mainly achieved in bound form with haemoglobin, i.e; as oxyhaemoglobin.
> Oxygen- haemoglobin dissociation curve or oxygen dissociation curve is a plot that represents the proportion of haemoglobin saturated by oxygen (oxygen saturation) against the partial pressure of oxygen in the blood.
Haemoglobin affinity for oxygen determines the curve.
Many factors affect this curve and tend to shift it either to left or right from the standard oxygen dissociation curve.
> Concentration of carbon dioxide or \[pC{O_2}\] and pH are the two major factors affecting the oxygen transport and thus the curve.
> The effect of these factors are explained by the Bohr effect which states that oxygen equilibrium curve of both fetal and adult blood gets shifted to right in response to a decrease in \[pH\]or increase in \[pC{O_2}\], or both.
It is observed that carbon dioxide affects the curve in two ways:
I) First, accumulation of \[C{O_2}\] leads to formation of carbaminohemoglobin.
II) Secondly, intracellular \[pH\] is influenced due to bicarbonate ion formation.
Reaction of carbon dioxide with water to form carbonic acid leads to drop in blood \[pH\].
> As a result, haemoglobin proteins release their oxygen load. Conversely, low \[C{O_2}\] levels in the blood raises \[pH\] and provides optimal binding conditions for \[{O_2}\] and haemoglobin.

Note:
Thus, low \[C{O_2}\]levels or low \[pC{O_2}\] favours optimal binding of haemoglobin and oxygen. Whereas, high \[pC{O_2}\] decreases the binding of haemoglobin and oxygen, shifting the oxygen dissociation curve to right.
At the alveoli, low \[pC{O_2}\] and high \[\;p{O_2}\] favours the formation of oxyhaemoglobin and at the tissue sites, high \[pC{O_2}\] and low\[\;p{O_2}\] favours the dissociation of oxygen from oxyhaemoglobin.