Carbon cycle

Step 2 - Activities

Let’s observe anaerobic respiration.

Let’s explain these questions we encounter in daily life with an activity;

What purpose do the bacteria serve in yoghurt fermentation?
Why does fermented dough rise in time?
Why does the taste of the wine enhance by aging?

Of two volumetric flasks, let’s fill one of them with water and sugar whereas the other also with yeast. Let’s place rubber balloons on the rims to prevent air leaks and wait for some time. What types of changes were observed for the balloons?



In the first volumetric flask containing only water and sugar, any changes (expansion) could not be observed for the balloon.

In the second volumetric flask, both sugar-water and yeast were present. The yeasts have gone through fermentation utilizing the sugar-water solution and produced CO2. The CO2 produced by fermentation has caused the balloon placed on the rim of the second volumetric flask to expand.