This test is to demonstrate the semi-permeability of a cell membrane.
Things Required:
Egg from experiment The Undressed Egg
Jar with a lid (the egg must fit in the jar)
Corn syrup
Directions:
Pour 3 inches (7½ cm) of corn syrup into the jar. Carefully place the egg in the jar. Close the lid, and allow the jar to stand undisturbed for 72 hours.
Compare the observation of the egg made in Experiment 68 The Undressed Egg with its appearance after soaking in the syrup. What caused the change?
This Is What Happens:
The egg drastically changes in size and shape. It has a rubbery outer skin with very little inside content.
Science Behind It:
The excess water inside the egg moves through the membrane into the syrup. The water-content outside the egg is much less than inside, thus the water moves out of the egg. The molecules in the syrup and other materials inside the egg do not move through the membrane because they are too large. This selectiveness of materials moving through the membrane is called semi-permeability.
