Final answer:
Starch did not diffuse through the dialysis tube membrane because its molecules are too large, unlike glucose which, as a smaller molecule, was able to pass through the selectively permeable membrane used in the dialysis process.
Step-by-step explanation:
In an experiment involving dialysis tubing, specific solutes may or may not diffuse through the membrane based on their molecular size. The dialysis tubing acts as a selectively permeable membrane, allowing some molecules to pass through while blocking others. In this context, starch did not diffuse through the dialysis tube membrane, because starch molecules are too large to pass through the pores of the membrane. Glucose, on the other hand, being a smaller molecule, was able to diffuse through the dialysis tubing.
Considering the provided additional information, starch is larger than several nanometers (4). To determine the size of glucose, a series of membranes with different pore sizes could be used. By observing which membranes allow glucose to pass through and which do not, the size range of the glucose molecule can be estimated.
Conclusion
Through experiments involving dialysis tubing and different solutions, it can be concluded that molecule size plays a crucial role in diffusion through semipermeable membranes. Starch, being a relatively large molecule, is typically not capable of diffusing through such membranes, whereas smaller molecules like glucose can.