Discussion questions:

What does yeast use sugar for?

What are two waste products that yeast produces?

What are three things the cell membrane does?

Remember how the characters in the Readers’ Theater imagined yeast in bread dough multiplying on and on forever? Do you think that’s possible? Why or why not?

Baker’s yeast is used for making bread; brewer’s yeast (a closely related kind of yeast) is used for brewing beer. Both kinds of yeast produce carbon dioxide waste. When there is no oxygen present, both kinds of yeast also produce alcohol (though the alcohol evaporates out of bread when it gets baked). Explain how the waste products of yeast are useful to beer makers. Where do you think the bubbles in beer come from?