Fermentation - Bewitched Balloons

Human Applications of Fermentation:

• • baking

  • wine, beer, champagne

  • biofuels

NGSS Cross-cutting Concept Standards

• Energy and Matter

  • Changes of energy and matter in a system can be described in terms of energy and matter flows into, out of, and within that system. (HS-LS1-5), (HS-LS1-6)

  • Energy cannot be created or destroyed--it only moves between one place and another place, between object and/or fields, or between systems (HS-LS1-7)

NGSS Disciplinary core idea standards

• • Organization for Matter and Energy Flow in Organisms

  • As matter and energy flow through different organizational levels of living systems, chemical elements are recombined in different ways to form different products. (HS-LS1-6),(HS-LS1-7)

  • As a result of these chemical reactions, energy is transferred from one system of interacting molecules to another. Cellular respiration is a chemical process in which the bonds of food molecules and oxygen molecules are broken and new compounds are formed that can transport energy to muscles. Cellular respiration also releases the energy needed to maintain body temperature despite ongoing energy transfer to the surrounding environment.(HS-LS1-7)

  • Cycles of Matter and Energy Transfer in Ecosystems

  • Photosynthesis and cellular respiration (including anaerobic processes) provide most of the energy for life processes. (HS-LS2-3)

Questioning Script:

Prior knowledge & experience:

• None

Root question:

• Why does one balloon grow in size without being inflated? How do you explain the other balloon not growing?

Target response:

• Yeast is undergoing cellular respiration or alcoholic fermentation and producing the gas carbon dioxide which blows up the balloon.

Common Misconceptions:

• Yeast is not alive

• Cellular respiration gives off air

Materials & Procedures:

Materials:

• balloons - 1 per flask

• 1000 ml flasks - 2

• sugar

• salt

• 400 ml warm water

• dry yeast - 2

Procedures:

• Prepare 2 equal size small plastic bags - one with a package of yeast and the other with an equal amount of sugar- label them both with the #1

• Prepare 2 equal size small plastic bags - one with a package of yeast and the other with an equal amount of salt - label them both with the #2

• Do not tell students what the bags contain

• Prepare 200 ml of warm water in each flask

• Ask a volunteer to help and have them pour the contents of both bags labeled one into one flask of warm water. Repeat with the bags labeled 2 in the second flask of warm water

• Students add 50 ml of warm water to each dry sample and stir

• Attach a balloon over the mouth of each flask

• Students can record a time lapse video of the results

Other Variations:

• Place yeast mixtures in balloons, press air out, and tie a knot

• Try different amounts of sugar

• Try different temperatures of water

Photographs and Movies: