50 Shades of Pink

Just a quickie this week as it’s that time of term.

The new OCR spec and Cell Membranes. The effect of temperature on membrane permeability is still there, and we’ve already 5-PAGGED (i.e. covered Practical Activity Group 5) with beetroot discs and colorimeters. Here’s my version of this old favourite.

beetroot practical updated 2015

It does strike me that this is a perfect example of allowing students to bring their phones to lessons in order to take photos of their work. By printing off the picture of their row of pink/red test-tubes and including it with their graph and table in the PAG portfolio, it’s excellent evidence for the OCR moderators to see on their school visit.

Anyway, in addition to the temperature effect, there is now the effect of solvents. So why not do this…

Return of the Beetroot. Membranes and Solvents

Depending on the ability of the class, you could get them to predict the effect, or explain their results after the event. Linking it to the use of soap for killing bacteria also makes them apply their thinking.

It works really quickly! They’ll see an effect within 5 minutes, if you like, and there will certainly be enough colour by the end of the lesson for a lovely photograph.


Time for coffee and pain au chocolat. Have a good week!


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