Why are cell so small?
In this practical, students are given Agar Cubes of three different sizes, impregnated with indicator to display an alkaline pH. Initial measurements make it clear that the surface-area-to-volume ratio is large for small cubes, with the ratio reducing as cube size increases.
Using Bromothymol Blue as the PH Indicator with Vinegar as the acid this offers a safer alternative to other common methods.
8 x 1cm cubes
8 x 1.5cm cubes
8 x 2.4 cm cubes
Please ensure cubes are kept in the fridge and out of light until ready for use.