Metabolism
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A respiratory physiology practical class - and beyond
PN had a physiology practical class on respiratory physiology, and the first exercise involved measuring the relative amounts of nitrogen, oxygen, and carbon dioxide in inhaled and exhaled air. The results were as follows:
inhaled |
exhaled |
|
| nitrogen | 78% |
78% |
| oxygen | 21% |
17% |
| carbon dioxide | 0.04% |
4.0% |
How and where has the oxygen been consumed?
Where has the carbon dioxide come from?
The oxygen has been consumed in the oxidation of metabolic fuels, mainly glucose and fatty acids, in various tissues, and the carbon dioxide is the product of that oxidation.
What are the three ways in which an organic compound may be oxidised?
removal of hydrogen
removal of electrons
addition of oxygen