Students use yeast to explore CO2 production by living organisms.
This is an excellent opportunity for students to design their own experiments to determine which variables affect the yeast’s ability to produce CO2.
Yeast is a fungal microorganism that feeds on sugar and produces carbon dioxide (CO2) plus ethanol. As the yeast feeds on the sugar, it produces carbon dioxide gas. This process is known as fermentation. The trapped CO2 accumulates inside the balloon, slowly inflating it.
A very similar process happens as bread rises. Carbon dioxide from yeast fills thousands of balloon-like bubbles in the dough. This is what gives baked bread its airy texture.
Since yeast also produces alcohol as it feeds, it is an important ingredient in beer & wine production.