Imaginative Teaching Resources & Inspirational Career Ideas from the Chilled Food Industry
Making science relevant by linking underlying principles to everyday applications is something that we have been thinking about as a department, so we were happy to trial the set of lessons produced by the Chilled Food Association. We chose lessons that would fit with our current teaching topics so the lessons were trialled across a range of ages and abilities and by different teachers.
Lesson 1 – the effect of pH on yeast activity in fruit juice; and the associated lesson plan suggests that this is most suited to KS3.
We felt that the concept of pH affecting the respiration of microbes was quite a difficult concept, so probably in the format suggested this is best for more able students, especially as the experiment does require a lot of effort in setting up. For lower ability groups, the equipment would need to be set up in advance.
We also found that not having access to enough water baths meant that we had to use beakers of water and keep these topped up to maintain the temperature. We also struggled to get the expected results, but that may have been because we couldn’t get the right type of grape juice, so we bought sugar-free and added glucose.
Setting the accompanying homework on food spoilage would serve as a good introduction to the lesson, and would give a little more context; although it can work equally for consolidation.
What we did find was that it was a useful activity in getting students to read and follow instructions for how to carry out a practical and although we didn’t get the results expected, it gave an opportunity for discussion.
The accompanying PowerPoint set the context well and the images served to engage the students.
Lesson 2 – Microbes in yoghurt is also aimed at KS3 students and involves staining bacterial cells to look at under the microscope. Again, the practical instructions are quite detailed and the practical takes time, particularly as it took over 10 minutes for the yoghurt drink to dry on the slide, putting pressure on the rest of the lesson.
Having some slide pre-prepared may help to ease this, or prepping the slides in one lesson to examine in another. Associated resources could be used in different ways, perhaps having the homework activity as something to do whilst the slides were drying.
Lesson 3 – The Pinking of Lettuce was aimed at KS4 and was trialled with a triple science chemistry class, linked to the testing of gases.
If carried out as suggested there is a lot of preparation in terms of making gases; we adapted by each group getting only one of the four gases to test and collating results. The tests must also be carried out over a couple of days, so lessons close to each other are a benefit. We did get conclusive results and the students enjoyed the demo where we set fire to a hydrogen balloon. Using the stalk of the lettuce gave the best results, so it might be a good idea to pre-chop the lettuce and give students pieces from different parts of the leaves. The associated questions on food spoiling were easy to answer using a biology book covering the legacy specification, but there was not sufficient content for a full hour’s lesson.
Lesson 4 – Modelling microbial growth. Although this could be used with either KS3 or KS4, it probably fits better with the latter, especially as it builds on some mathematical concepts such as exponential growth and logarithmic scale – the serial dilution pH activity is a good demonstration of this. The lesson requires students to have access to computers, to log on to the ComBase website. Again, the lesson is probably better suited to more able students, as it covers a few more challenging concepts and requires students to work more independently. The MicroTrumps cards are an engaging resource which students enjoy using.
Lesson 5 – Species variation and genetic adaptation. This lesson was tackled by a lower ability Y9 class, who had recently started their GCSE and it linked well to their previous work on adaptations and the structure of bacteria. In the starter students were able to recall the definitions of adaptation and variation. The main activity involved the use of the eye-catching MicroTrumps cards which described the different bacteria and from which students were able to decide which bacteria would survive best under different conditions and to explain why it is important that the bacteria do not kill their host. The accompanying TED talk contained relevant information about antibiotic resistance, though it may be too advanced in part and there was possibly not enough content to the lesson for a more able group.
All in all, the resources are well developed and engaging and provide a good starting point for teachers to adapt to the needs of their students.
This article originally appeared in the Association of Science Education’s School Science Review (September 2017). It is reproduced by kind permission.