The purpose of this experiment was to understand osmosis and see this through the cell membrane of the egg. This shows the passive transport, movement of substance, across the membrane. Diffusion is the movement of molecules from an area of higher to lower concentration. Osmosis is the movement of water across semi-permeable membrane. It moves water molecules across cells via diffusion. Its direction depends on the concentration.
Experiments with chicken eggs were used as an enlarged metaphor (cell) to monitor process of water transport (osmosis) into and out of the cells. This provided an awareness of how, after receiving an electrical signal triggered by touch in specialised plants (i.e. mimosa pudica), the affected cells would response through process of osmosis, where water is rapidly drawn out of these cells to induce immediate leaf closure.
Two eggs were placed in vinegar solution, 25 May 2007
Immediately bubbles (carbon dioxide) formed on the surface of the egg.Vinegar causes egg shell (calcium carbonate) to disappear, layer by layer, 25 May 2007Three days later, the eggs are 'shell-less', 28 May 2007One of the 'shell-less' egg was placed in syrup solution (the other egg remains in vinegar solution), 28 May 2007The following day, noted that the egg in the syrup had shrivelled up, water moved out of the egg (hypertonic), 29 May 2007 The shrivelled up egg was transferred into water solution, 29 May 2007.The egg in water solution starts to enlarge to original size. But stayed at equilibrium and was same size as the eggs in the fridge. It's isotonic as there is no movement of water into and out of the egg, 29 May 2007Osmosis in action, 30 May 2007The egg in the vinegar solution enlarged, water moved into egg (hypnotic), 30 May 2007 Note difference between the shell-less eggs. The enlarged one of the left is in vinegar solution, whilst the egg on the right in water solution is 'normal' size.