AP BIOLOGY

Detailed explanation-1: -Even when equilibrium is reached, particles do not stop moving across the cell membrane. Although it may seem as if the concentrations are not changing, nearly equal numbers of particles cross the membrane in both directions. This means that there is no net change in the concentration of the substances.

Detailed explanation-2: -Even when equilibrium is reached, particles of a solution will continue to move across the membrane in both directions. However, because almost equal numbers of particles move in each direction, there is no further change in concentration.

Detailed explanation-3: -It is natural to assume that osmotic equilibrium is a point at which the osmotic pressure of the solutions on each side of the membrane becomes equal. At this point, the net transfer of water across the membrane is zero.

Detailed explanation-4: -The end result is an equal concentration, or equilibrium, of molecules on both sides of the membrane. At equilibrium, movement of molecules does not stop. At equilibrium, there is equal movement of materials in both directions.

Detailed explanation-5: -Molecules move from an area of high concentration to an area of lower concentration until an equilibrium is met. The molecules continue to cross the membrane at equilibrium, but at equal rates in both directions.