Dr. Art's Guide to Planet Earth , pages 62-65.
Respiration is an important part of the global carbon cycle.
That means they internally burn sugars back into carbon dioxide gas which is then released into the atmosphere. We can use yeast to experiment with and explore this process. Human activities that change conditions in the air, water and land affect other organisms. We can add different chemicals to the yeast and determine what effects they have by measuring any differences in the observed respiration. Wear safety glasses and dispense chemicals in small quantities.