Questions: 1. How is a cell membrane like the plastic bag in the experiment?
2. Define diffusion.
3. List two reasons why molecules will not diffuse into cells.

Explanation:

1. cell membranes are partialy permeable, only allowing passage to some certain molecules.

2. diffusion is the movement of molecules across partially permeable membrane down concentration gradient.

3. the molecules are too big to pass through partially permeable membrane. the concentration of the molecule might be higher in the cell than in the solution/surroundings.