Activity 1: Fermentation Factories

How can we create ethanol? What does the process of fermentation produce?

Preparation: Create the following bags 25–30 minutes prior to class. If possible use warm water (95° F/35° C) to hydrate the fermentation bags. Remove all of the air from the bags, seal, and incubate the bags in a warm location (98.6° F/37° C) for optimum fermentation. Remove the bags from the incubator and ask the students what they are observing. Allow the students to generate discussion with their observations. Do not confirm or deny ideas as you lead the conversation with your students.

1. Give each student one copy of the Fermentation Factories student handout.
2. Write the ingredients of each bag on the board and have students brainstorm observations or questions surrounding the function of each ingredient individually for 1 minute. Have them record both the bag contents and their observations on their charts for later use.
3. Next, have the students share their observations in a small group for three minutes. Generate class discussion by asking groups to share their observations with the class. Possible observations or questions about the corn fermentation in a bag ingredients:
   • Glucose is a simple sugar (monosaccharide).
   • Yeast are organisms/decomposers that eat sugars.
   • Starch is a complex sugar (polysaccharide).
   • Fermentation occurs when yeast consume sugar (glucose) and produce alcohol (ethanol) and carbon dioxide.
   • Bag A produced the most CO2 in 20 minutes (glucose).
   • Bags B and C produced very little CO2 in 20 minutes.
   • Bag D produced the second largest amount of CO2 in 20 minutes.
   • What do amylase and glucoamylase do? How do they function with sugars or yeast?
4. Read the challenge to the students: Create the greatest volume of ethanol (measured by the volume of CO2 generated) in the fastest time possible.
5. Students should work in groups of 2–3 individuals for this challenge. Review the following criteria and constraints for the challenge.
   • Plan an (several) experiment(s) to produce ethanol in a small bag environment.
   • You can only use the following materials/amounts provided.
   • You have 1 or more class period(s) to experiment on your initial design(s) based on your plan.
   • Data must be collected and analyzed to provide evidence for your conclusion.
   • Report back to the class and provide future experimental designs as a result of your current data/conclusion.
6. Provide some, all, or additional material items to the students that are listed above.
7. Discuss the engineering design process with your students. Encourage student groups to create two or more experimental designs based upon their knowledge of what occurs in the phenomena bags. Why are they investigating their design? What is their reasoning for their materials? What patterns do they expect to see? They will also need to create a method for measuring their CO2 gas. We suggest that they measure volume by height displacement using a clipboard and ruler to demonstrate their volume change in CO2 gas.
8. Students should be able to predict the outcome of some of their experimental designs based upon previous background knowledge and their observations of the anchoring phenomena.
9. Encourage the students to create charts and graphs to show the volume change within their bags over time. Students should create their own experimental procedure to collect and record data.
10. Students should create a model of their fermentation ecosystem. The students can draw what is happening in the anaerobic process of fermentation based on the data collected in their experimental models.
11. Create a discussion with your students to determine if they could improve upon their experimental design based upon the evidence presented. What could they improve upon? Materials used? Experimental conditions? What research could they do to make their design as efficient as possible?
    • Can you create a more efficient design using different materials?
    • Can you predict the outcome of other experimental designs?
    • How can you change you original design to become more efficient by changing the experimental conditions?
    • Make predictions using all of the available feedstocks in separate designs to determine which one will make the most CO₂ over time.

Activity 2: Ticketase

What roles do different enzymes play in the fermentation of starch?

1. Give each student one copy of the Ticketase student handout.
2. Remind the students of the 4 fermentation bags used in Activity 1. What was occurring in each of the four bags? You can help guide the students’ discussion by asking questions as you record their observations/questions.
   • How did the amylase and/or glucoamylase impact the fermentation reaction?
   • What are the roles of amylase and glucoamylase?
   • Did amylase/glucoamylase help the fermentation process occur more slowly, rapidly, or have no net effect?
3. Have students work together in groups of 4. Provide each group with 3 strings of 50 connected tickets. Instructions for the activity are included on the student page.
4. Refer to the Ticketase Teacher Key for answers to the handout, ideas for differentiation, and a rubric for assessment.