Reflection: Real World Applications Yeast & Bananas Investigation - Section 3: Explore


Even though the class decides to "observe and record each day," I check on the bananas each day to determine if enough of a change has happened to warrant getting the supplies out and documenting observations. It's not until day 8 that I notice enough of a change! During our Day 8 observation, the process takes about 20 minutes. I hand out the following Observation Notes page to each student. I know it may seem backwards, but we ended up discussing what the bananas in both bags looked like before (at the beginning of the investigation) and after (after 8 days). It actually turns out to be a great review. 

In order to complete the observation process, I invite one student from each team to retrieve their team boxes. I ask students to NOT OPEN THE BAGS. I also warn students that the boxes would REALLY smell after opening them... and they did: Smelly Bananas! If I knew they were going to smell this badly, I would have opened them the night before to air out! 

Here's what the bananas looked like side by side: Bananas With & Without Yeast and here are a few examples of student observation sheets: 


As student finish with their observations, we discuss what they notice as a group. One group points out that the banana without yeast is green and moldy. The banana with yeast is darker brown and mushy. The banana without yeast is larger while the banana with yeast is smaller and more decomposed. Some students pointed out that the bag with yeast had more air inside it. Others commented that the banana with yeast smelled like wine or beer. We then discussed real world applications: as yeast breaks down (decomposes) the sugar in the bananas, ethanol and carbon dioxide are created. This is why yeast is used for both bread-making (the carbon dioxide helps the bread rise) and wine-making (ethanol is alcohol). 

  Real World Applications: Day 8 Observation
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Yeast & Bananas Investigation

Unit 2: Ecosystems
Lesson 8 of 28

Objective: SWBAT explain the role of decomposers in an ecosystem.

Big Idea: In this lesson, students will be continue learning about decomposers, including mold and yeast, which are both types of fungi. Then, students will complete an investigation using bananas and yeast!

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11 teachers like this lesson
ecosystem, Science, Scientific Method (Science Skills), global warming, abiotic factors, yeast, investigation, Decomposers, decomposition, biotic
  60 minutes
banana with yeast
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