The Medical Effects of Carbon Dioxide on the body

A Diagram of the Respiratory System In respiration oxygen is used to convert organic matter into carbon dioxide and yield energy to the cells in the body. It is transported around the body by haemoglobin in the blood. Blood is pumped around the body by the heart and the oxygen and carbon dioxide gases diffuse in and out of the blood due to the relative partial pressures of the gases. Each gas will travel from areas of high partial pressure of that gas to areas of low partial pressure.

In an atmosphere rich in carbon dioxide the partial pressure of carbon dioxide in the air will be greater than that in the blood so more CO2 will diffuse into the blood. An enzyme in the blood catalyses the following reactions of CO2;

CO2 + H2O « H2CO3 « H+ + HCO3-

As the concentration of CO2 in the blood increases the reactions will proceed to the right, increasing the concentration of hydrogen ions in the blood and reducing the pH. Hydrogen ions combine with the protein part of haemoglobin and change its 3-D structure, decreasing its ability to bind with oxygen. Therefore an increase in CO2 in the air will make respiration more difficult. In a dense CO2 atmosphere respiration will be completely stopped as there will be no intake of oxygen at all, resulting in suffocation.


The basic equation for respiration is CH2O + O2 ® H2O + CO2

pH - a measure of hydrogen ion concentration; pH = -log10[H+] A low pH indicates a high concentration of hydrogen ions, i.e. acidic conditions.