Interest in Science is on the rise in Year 5!

Experiment 1

Experiment 1

Year 5 are studying micro-organisms in Science lessons. We have been investigating yeast, a tiny living thing that can do amazing things.  We have conducted some experiments. Firstly we wanted to know what yeast needs to ‘work’ best. We set up an experiment with 4 bottles. Bottle 1 had yeast and warm water, Bottle 2 had yeast, sugar and warm water, Bottle 3 had sugar and water and Bottle 4 has sugar and yeast. We made predictions about what would happen and also observed what was happening during the experiment. After 1 hour this photo shows what had happened.It is clear that in Bottle 2 the balloon inflated faster and bigger than the rest.  After discussing our findings (and some more research) we discovered that sugar is food for the yeast and the water activates the yeast.  The reaction between the yeast, sugar and warm water creates the gas called carbon dioxide which causes the balloon to inflate.

Today we continued our investigation to see which temperature the yeast likes best.  Again, we placed yeast and sugar in bottles.  We added cold water to bottle 1 (white balloon), warm water to bottle 2 (green balloon) and boiling water to bottle 3 (red balloon). We made predictions and recorded our observations.  This is what the bottles looked like after 45 minutes. What do you think has happened in each bottle?

Experiment 2 45 mins

Experiment 2 after 45 mins

What temperature do you think yeast likes the best?

We also know that yeast is a very important ingredient in bread. We are going to make some bread soon.

Can you explain why yeast is important in breadmaking? Do our Science experiments help you to understand?

Experiment 2 after 120 minutes

Experiment 2 after 120 minutes

3 thoughts on “Interest in Science is on the rise in Year 5!

  1. Hi Mrs Thomas and fellow bloggers,

    I really enjoyed our science experiment, and I am looking forward to learning more about Micro-Organisms next term.

    I have been thinking about the questions you have asked and I think I have a pretty good answer exept I am not sure that it would be right or wrong.

    The first question asks what temperature do you think yeast likes the best?

    I think the temperature yeast likes the best is warm, not too hot and not too cold, I think the reason for this is because in bottle 2 the bottle had yeast, suger, and warm water. You could clearly see that bottle 2 was the bottle thats balloon really blew up, and I think the reason for that was because of the warm water.

    Can you explain why yeast is important in breadmaking?

    I think yeast is important in the bread making because yeast is the thing that needs to have food and its what makes the huge bubbles in bread.If there was no yeast in bread, and nothing for the yeast to eat, the bread wouldn’t rise up and if the yeast had nothing to eat, then it wouldn’t make the bubbles that it causes in bread.

    Do our Science experiments help you to understand?

    I think that our science experiments help us to understand alot about Micro-Organisms, how they are made, what yeast is made of how different ingridiants react to different things and how mostly yeast reacts to different things. On Wednesday, my class watched a video about yeast and how it reacts to different things, ingridiants were placed in different bags, and they were left for one hour and a half, we found out that oil and salt are foods that yeast don’t like to eat and with those foods, yeast does not produce CO2 which causes the bubbles in bread.

    I have loved science so much this term and last term and I can’t wait to learn more next term!

  2. Hey there Mrs Thomas!
    I hope that you enjoy these holidays!
    The 2nd balloon in that 1st pictures of that post, the balloon is soooooo inflated!
    That science experiment was fun, even though I was only there for the observing because I was downstairs with Mrs Daly.
    I hope we can do some more stuff like this next term!!
    From Jess

  3. Hi Mrs Thomas,

    The first experiment was really fun even though our group’s balloons didn’t really blow. Some people’s balloons blew up really fast. It could have been the air temperature the balloon could have not been fasted tight enough. It was interesting finding out how yeast reacts to sugar waster. I would have know this things if I hadn’t moved schools.I had fun seeing what ingredients blow up with yeast.

    What temperature do you think yeast likes best?

    I think that yeast likes warm water. The reason why I think that it doesn’t like hot water is because it kills the yeast and the yeast is a living thing just like me and you. Boiling water can hurt us but not kill us. I don’t think that it likes cold water because it is to cold. It has blown up in the photo but it could be different outside.

    Can you explain why yeast is important in bread making?

    I think that yeast is important in bread making because it makes the bread rise. If we didn’t have yeast every bread would be flat. In the old old days the poor people use to eat flat bread because they didn’t have yeast.

    Do our Science experiments help you to understand?

    Yes they do. It helps me understand why yeast rises and why we need yeast.
    Sarah P

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