1. Exercises
  2. Energy
  3. A respiratory physiology practical class - and beyond

A respiratory physiology practical class - and beyond

Objectives

By the end of this exercise you should be able to:

  • Explain in outline how oxygen is consumed and how carbon dioxide and water are produced in the oxidation of metablic fuels
  • Explain how oxygen reaches tissues where it is required
  • Describe in outline how metabolites may undergo oxidation
  • Explain what is meant by a metabolic pathway
  • Explain how it is possible to ensure unideirectional flux through a pathway even when all enzyme-catalysed reactions are reversible

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?