What are the three ways of Co2 transported within blood

Question

Please I need help with question

Answer 1

Another way to add to the above great answer is the following:

In the blood...

1. about 5% of the carbon dioxide (CO₂₎ is carried in solution in the plasma
2. about 20% of the CO₂ is transported by combining with hemoglobin (Hb)
3. and about 70% of the CO₂ is transported via a rapid conversion to bicarbonate ions (HCO₃^-); when in the lungs, the process is reversed upon exhalation

Answer 2

Hi, Sami! Great question!

When the cells of our body produce CO₂ as a waste product of metabolism, there are three ways that the CO₂ can be transported back to the lungs to be expelled.

1. Firstly, CO₂ can undergo a reaction commonly referred to as the "bicarbonate buffer system". Through this reaction CO₂ is effectively converted into bicarbonate ions (HCO₃-). These bicarbonate ions, being more water soluble than CO₂ are therefore more soluble in the blood. Once at the lungs, the bicarbonate ions are converted back into CO₂ and exhaled.
2. Secondly, CO₂ can bind to blood transport proteins called hemoglobin. Although hemoglobin is commonly thought to be exclusively a "oxygen-transport protein", hemoglobin also contains non-oxygen binding sites that CO₂ can bind to. These hemoglobin transport the CO₂ molecules to the lungs where they are exhaled.
3. Lastly, to a small extent, CO₂ can be directly dissolved in the plasma of the blood itself. In other words, CO₂ can diffuse into the blood from tissues where it travels through blood vessels to the lungs. Note that only a small portion of the total CO₂ transported to the lungs uses this method.