Yeast Blowout...a growing relationship (Athena Meltzer)

Author

Athena Meltzer

Principle(s) Illustrated

• Alcoholic fermentation by yeast cells. In brewing, alcoholic fermentation is the conversion of sugar into carbon dioxide gas (CO2) and ethyl alcohol. This process is carried out by yeast cells using a range of enzymes. ... These yeast cells gain energy from the conversion of the sugar into carbon dioxide and alcohol. The greater the amount of sugar the more carbon dioxide gas is produced.

Standards

• NGSS Science & engineering standards

  • Developing and Using Models

    • • Constructing Explanations and Designing Solutions

      • Engaging in Argument from Evidence

• NGSS Cross-cutting concept standards

  • Cause and Effect

§ Cause and effect relationships may be used to predict phenomena in natural or designed systems. (MS-LS2-1)

• • Energy and Matter

§ Matter is conserved because atoms are conserved in physical and chemical processes.

(MS-LS1-7)

§ Within a natural system, the transfer of energy drives the motion and/or cycling of matter. (MS-LS1-6)

§ The transfer of energy can be tracked as energy flows through a natural system. (MS-LS2-

• • Stability and Change

§ Small changes in one part of a system might cause large changes in another part.

(MS-LS2-4)

• NGSS Disciplinary core idea standards

  • • PS3.D: Energy in Chemical Processes and Everyday Life

    • § Within individual organisms, food moves through a series of chemical reactions in which it is broken down and rearranged to form new molecules, to support growth, or to release energy. (MS-LS1-7)

• • LS2.A: Interdependent Relationships in Ecosystems

  • § Organisms, and populations of organisms, are dependent on their environmental interactions both with other living things and with nonliving factors. (MS-LS2-1)

Questioning Script

Prior knowledge & experience:

• Students are familiar with scientific method and making observations.

• They know what an independent & dependent variable is and how to set up a controlled experiment.

• Students are familiar with cellular respiration, fermentation and the difference between the two.

• Some students may know that yeast causes bread to rise but may not know that it is due to carbon dioxide bubbles getting trapped by the dough.

• Vocabulary: Independent variable, dependent variable, constant, controlled experiment, hypothesis, qualitative & quantitative observation

Root question(s):

1. Does this reaction show cellular respiration or fermentation? Explain.

2. If more sugar is added to the yeast and water, will more carbon dioxide gas be produced?

3. Is there a way we measure if more sugar yields more carbon dioxide gas?

4. Is there a way to verify that carbon dioxide gas and not oxygen gas is being produced?

5. Justify why this demonstrates fermentation and not cellular respiration.

Target response:

If more sugar is added to the yeast, the reaction will be greater and more carbon dioxide will be produced. We will be able to observe this because the balloon that increases in size the most will be over the bottle with the greatest amount of sugar.

This is fermentation because there is no oxygen present so the reaction is anaerobic. Yeast, sugar and water break down into carbon dioxide and alcohol.

Common Misconceptions:

This is an example of fermentation, NOT cellular respiration because students overlook the fact that there is a lack of oxygen in the reaction.

Photographs and Movies

• • • Analyzing and Interpreting Data