The secondary Biology class recently was engaged in doing a laboratory experiment investigating the diffusion of starch, glucose and water through a membrane. The students learned how to test for the presence of starch and glucose in solutions so that they would be able to know if these substances were present in their solutions at different stages of their experiment. Students measured and weighed specific amounts of the each of the solutions and then added them to dialysis membrane bags, which would allow some substances to pass through them, while other substances were not able to pass through them. By measuring how the weight of the dialysis membrane bags changed over a period of time, the students were able to predict which substances entered or left the dialysis membrane bag. If the bag
changed its weight, it was proven that some substances diffused through the bag.