Last week we went to South End Junior School to teach the year 4s and year 5s how to do some experiments! On Tuesday we met the year 4s, and told them all about exothermic and endothermic reactions. We used yeast and hydrogen peroxide for the exothermic experiment: it bubbled up and got warmer. Then we used bicarbonate of soda and white vinegar for the endothermic experiment: it fizzed and got colder! We asked the year 4’s which reaction they thought happened inside their bodies to keep them warm: every class got it right and said Exothermic. The children were very enthusiastic about the experiments and wanted to know more.
The other experiment we did was extracting DNA with Year 5. They did it themselves and really enjoyed it. First we asked the classes if they knew what DNA does: lots of them knew it makes us all different and who we are, but they didn’t know that is also the instructions that make us grow into humans, all living things have different instructions in their DNA. But lots of the DNA is the same: did you know that half our DNA is the same as in a cabbage! We extracted the DNA from peas, using a pestle and mortar, alcohol, salty water and washing up liquid. This was to crush up the peas, then break up the pea cells to get the DNA out of them. Adding the ethanol made a cloudy layer appear: this is the DNA!
We really enjoyed getting to be the “teacher” for a lesson, and going to another school to show them the kind of things we do in the lab is great!