Question
4 Explain the differences in the air breathed into the lungs and the air breathed out of the lungs. [4 marks] Do not w outside box
Answer
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(223 Votes)
Paige
Master · Tutor for 5 years
Answer
The air breathed in is richer in oxygen, approximately 21%, and contains a fraction, about 0.04%, of carbon dioxide. The metabolism of cells absorbs much of this oxygen, facilitating it to be exhaled as a blend of nitrogen (~78%), reduced oxygen (~16%), and carbon dioxide (~4%). Thus, these differences occur due to the processes of gas use and creation within the body.
Explanation
## Step 1When humans breathe, air inhaled is always different from the air exhaled. We can explain this by taking note of the composition and some basic properties of the air that is being breathed.## Step 2In our atmosphere, normal 'pre-breathing' air includes primarily oxygen and nitrogen mixed with tiny amounts of other gases, while the amounts of these constituents are differing in exhaled air.### For gas contents: - The main body of inhaled air holds
nitrogen,
oxygen and approximately
of carbon dioxide while in trace amounts, it shares other gases.- The body uses much of the inhalable air oxygen for cell metabolism, and replacing it by exhaling with a mixture of
nitrogen, but approximately
oxygen and
of carbon dioxide now.