Today’s experiment will involve yeast and decomposing bananas. Does anyone know
what yeast is? Allow the students to give their answers. Yeasts are single-celled fungi which are
commonly used to leaven bread, ferment alcohol, and even drive fuel cells. Ask students “what is
a fungus?” They should remember that fungi are decomposers. Give an example of how yeast
breaks down food (glucose → ethanol + carbon dioxide). Include chemical formula. Yeast can
operate aerobically or anaerobically. Define aerobic and anaerobic