Biology
Cellular respiration and fermentation are 2 of the most challenging concepts for introductory biology students, who may become so consumed by memorizing steps of the Krebs cycle and glycolysis that they lose sight of the big picture. The following demonstrations place aerobic cell respiration and fermentation firmly in grasp. First, students observe respiration in germinating seeds by detecting the carbon dioxide produced. Next, they observe the carbon dioxide gas produced by yeast fermentation.