Decomposing Bananas Mrs. Turner’s 4 th Grade Class

Ask A Question  What causes food to spoil?  Does dry yeast make food spoil faster?

Write A Hypothesis  We think that the banana slice WITHOUT the dry yeast will spoil faster than the banana slice WITH dry yeast because we think that the dry yeast will protect the banana from the air.

Make A Prediction  If the banana slice has no yeast on it, then it will spoil faster because of the air exposure.  If the banana slice has yeast on it, then it will spoil slower than without because the yeast is protecting the banana from air.

Perform Experiments 1)Put a banana slice in each bag. Label one bag P for Plain. 2)Sprinkle 2/3 spoonful of dry yeast on the other banana slice. Yeast is a Decomposer so label this bag D. 3)Seal both bags. Put the bags in the same place. 4)Check both bags every day for a week. Observe and record the changes you see in each bag.

Perform Experiments BagDay 1Day 2Day 3Day 4Day 5 P 3.5 cm White/yellow color Smells like a banana D 3.5 cm Covered in dry yeast – brown Smells like Cheerios Day 1 - PlainDay 1 - Decomposer

Perform Experiments BagDay 1Day 2Day 3Day 4Day 5 P 3.5 cm White/yellow color Smells like a banana 3 cm White/brown/ yellow color Smells like rotten banana D 3.5 cm Covered in dry yeast – brown Smells like Cheerios 3 cm Covered in dry yeast – white Smelled like rotten grapes Day 2 - Plain Day 2 - Decomposer

Perform Experiments BagDay 1Day 2Day 3Day 4Day 5 P 3.5 cm White/yellow color Smells like a banana 3.5 cm White/brown/ yellow color Smells like rotten banana 3.5 cm Brown/black/ off-white color Smells like an old banana D 3.5 cm Covered in dry yeast – brown Smells like Cheerios 3.5 cm Covered in dry yeast – white Smelled like rotten grapes 3.5 cm Covered in dry yeast – brown Smells like Cheerios and old milk Day 3 - Plain Day 3 - Decomposer

Perform Experiments BagDay 1Day 2Day 3Day 4Day 5 P 3.5 cm White/yellow color Smells like a banana 3.5 cm White/brown/ yellow color Smells like rotten banana 3.5 cm Brown/black/ off-white color Smells like an old banana 3.5 cm Brown/black/off -white color Smells like an old banana D 3.5 cm Covered in dry yeast – brown Smells like Cheerios 3.5 cm Covered in dry yeast – white Smelled like rotten grapes 3.5 cm Covered in dry yeast – brown Smells like Cheerios and old milk 3.5 cm Covered in dry yeast – tan Mushy Smells like fresh bread Day 4 - Plain Day 4 - Decomposer

Perform Experiments BagDay 1Day 2Day 3Day 4Day 5 P 3.5 cm White/yellow color Smells like a banana 3.5 cm White/brown/ yellow color Smells like rotten banana 3.5 cm Brown/black/ off-white color Smells like an old banana 3.5 cm Brown/black/off- white color Smells like an old banana 3.5 cm Brown/black/off- white color Smells like an old banana D 3.5 cm Covered in dry yeast – brown Smells like Cheerios 3.5 cm Covered in dry yeast – white Smelled like rotten grapes 3.5 cm Covered in dry yeast – brown Smells like Cheerios and old milk 3.5 cm Covered in dry yeast – tan Mushy Smells like fresh bread 3.5 cm Covered in dry yeast – tan Mushy Smells like fresh bread Banana is disappearing Day 5 - Plain Day 5 - Decomposer

State Your Conclusion o It turns out that our hypothesis was incorrect. The banana slice with the yeast spoiled faster. The yeast ate the banana slice. Yeast is a decomposer which means that it eats the remains of producers/consumers. A banana is a producer.