Yeast is a BEAST!
This afternoon, we continued our adventures into our topic of Living Things and Their Habitats. So far, we’ve looked at classifying animals (including vertebrates and invertebrates), classification keys and plants, and now we have begun exploring the weird and wonderful world of microorganisms!
We started by discussing what microorganisms actually are, with the prefix ‘micro-’ being a rather big clue to something very small! We talked about the use of microscopes and discovered that microorganisms can be both helpful and harmful.
Most of the time, when they are in the right place, the majority of microorganisms are not harmful to people. In fact, they often do a great deal of good, from breaking down waste to helping us make bread. We couldn’t live without them!
However, some microorganisms can be harmful and make us ill. Some can enter our digestive system and cause illness, while others can give us a cold. Certain microorganisms can also cause infectious diseases, such as chickenpox or measles.
We then reminded ourselves of MRS GREN and focused specifically on respiration. The children were set the task of drawing a labelled diagram and predicting what would happen when we mixed warm water, yeast and sugar together.
The scientific vocabulary on display was superb, and the children were able to draw upon their own experiences, particularly baking, to help with their scientific enquiries. Here is one fantastic example of a prediction:
“I think the balloon will inflate because the yeast is a living organism that respires. As it respires, it produces carbon dioxide, which is a gas. I know that bubbles of gas are produced as bread is made and this forms the ‘holes’ in the bread. The gas produced has nowhere to escape, so it will expand to fill the balloon.”
That is some serious scientific thinking!
The children then worked in threes, chugged the water from their plastic bottles (it would have been rude to waste it, and science is thirsty work!) and began carefully following the method to carry out the experiment.
Once all the components had been pieced together, the bottles were placed outside in the sunshine while we headed off to assembly. Then came the waiting...
Secretly, we moved the bottles onto the table outside our classroom so that, when the children returned from assembly, they were greeted by a wonderful sight: inflated balloons! The yeast had indeed proved that it really is a BEAST!
It was an incredibly fun experiment, packed with excellent scientific discussion, predictions and plenty of excitement. We’ll continue our microorganism adventure next week in our final lesson of the topic.
Who knew something so tiny could cause so much excitement?
