Question

In an experiment involving planar bilayers, a solution of table salt (sodium and chloride ions in water) is added on the left side of the membrane while pure water is added on the right side. after 30 minutes the researchers test for the presence of ions on each side of the membrane. the right side tests negative for ions. what can you conclude?

Answer 1

The membrane separating the left side and the right side is impermeable to ions. In a semi-permeable membrane (i.e. plasma membrane), selected molecules can freely cross the membrane by diffusion depending on the size and charge. In this case, the membrane is purely impermeable that's why there was no diffusion that happened.