How does surface area to volume ratio limit the size of cells? Safety Hair tied up, wear lab coat, wear safety glasses, use scalpel with care,, stand up for the duration Equipment Plate of agar soaked with phenolphthalein 1 x Large bottle of Hydrochloric acid 3 x beakers 1 x 30cm ruler 1 x pair of forceps 1 x Scalpel 1 x Stop clock Tissue paper Method Cut out agar cubes (1.5cm3, 1cm3, 0.5cm3) Place a cube in a beaker and cover with hydrochloric acid Start the stop clock – time how long it takes all colour to go (you can periodically stir the solution) Remove the cubes from the acid using forceps and place onto the tissue paper Repeat if time for different sized cubes and work out the average time Related skills Surface area to volume ratio is important in the limitation of cell size Topic 1 Hours 1.5