Question

With 40% glucose in the sac and 40% glucose in the beaker, would you expect to see any net movements of water (osmosis) or of glucose molecules (simple diffusion)?

Why or why not?

Answer 1

No net movement of water (osmosis) or glucose (simple diffusion) would occur when a sac and beaker both contain 40% glucose due to the isotonic condition and dynamic equilibrium.

Step-by-step explanation:

Osmosis and Diffusion with Equal Glucose Concentrations

When a sac contains 40% glucose and the beaker outside it also contains 40% glucose, there would be no net movement of water (osmosis) or glucose (simple diffusion) because the concentrations on both sides of the membrane are equal. This scenario is known as an isotonic condition where the concentration of solutes (in this case, glucose) is the same inside and outside the cell, leading to dynamic equilibrium. At dynamic equilibrium, while individual molecules may move across the membrane, there is no net flow in any direction because the forces driving movement in one direction are balanced by those driving movement in the opposite direction.

In this particular setup, since there is no concentration gradient for glucose across the membrane, no net flow of glucose would occur. Similarly, water molecules would move across the membrane at equal rates in both directions, maintaining the equilibrium. This is a key concept in osmosis, where water moves from areas of lower solute concentration to areas of higher solute concentration, until equilibrium is reached. However, in this case, as the concentrations are already equal, no osmosis is observed.