Question
In what way air breathed in differs from the air breathed out during respiration? How much water one loses daily from the body by breathing?
Solution
During respiration organisms use oxygen and give out CO2. Therefore, the air breathed in contains more percentage of oxygen and less percentage of carbon dioxide. The air breathed out contains more percentage of carbon dioxide and water vapour and less percentage of oxygen. A comparison of composition of air breathed in and breathed out is given in the table below:
Composition of Respired Air
|
Content |
Air breathed in (Approx) |
Air breathed out (Approx) |
|
Nitrogen |
79% |
79% |
|
Oxygen |
21% |
17% |
|
Carbon dioxide |
0.04% |
4% |
|
Water vapour |
Varies |
Saturated |
One loses approximately 400 cm3 of water daily from the body by breathing.
