How does materials move through Semi-permeable membrane?

Answer 1

The movement of water through a semi-permeable membrane from an area of low solute concentration to an area of high solute concentration is called osmosis.

Osmosis. It is the movement of solvent molecules through a selectively permeable membrane into a region of higher solute concentration. Osmosis tries to level the concentration of solute on both sides of the membrane.

The movement of water molecules across a selectively permeable membrane is known as osmosis.

Answer 2

The mechanism driving diffusion is highly dependent on both the membrane and the permeating medium.

Water permeation:

In most porous mambranes, the pressure difference across the membrane is the dominating driving force. Once the pressure overcomes the surface tension of water, it is simply pushed through the membrane. The required pressure is strongly dependent on the pore size.

For non-porous membranes (some plastics like polyethylene and polypropylene), the water vapour pressure difference across the membrane is the driving force. The water vapour pressure is strongly dependent on temperature, so the permeability rate is increased when the temperature is increased. In this case, there are some tiny voids between the molecular chains usually called 'free volume'. Water can enter these voids, and can 'jump' from void to void due to a continuous redistribution of the free volume. This redistribution is caused by thermal movement of the long molecular polymer chains, explaining why temperature has such a large impact. Even though the movement of a single water molecule is random, there is a net transport of water from one side to the other. This is simply because there are fewer water molecules (lower concentration) at the downstream side of the membrane than at the upstream of the membrane.

If there are differences in the salt concentration across the membrane, an osmotic pressure is set up. This pressure can also be the driving force. Generally speaking, the driving force is the 'chemical activity' gradient, which in some cases also can include temperature and electrical field.

For more technical information, I would like to refer you to the book 'Basic Principles of Membrane Technology' by Marcel Mulder.

Answer 3

since lipid membranes are selectively permeable, only certain things can cross easily. only hydrophobic, and small things can enter. anything Hydrophilic or larger than the ports cannot enter, and neither can anything that is charged. Non-permeable items enter through transport proteins. facilitated diffusion is the random movement of solutes across membranes through transport proteins...this does not require energy (a good example is aquaporins..) not everything can enter a semi-permeable membrane..

Answer 4

if you have this packet the answer is B) diffusion, osmosis

Answer 5

In plasma membrane, water moves through using the protein aquaporin.

It follows the law of diffusion to move as per osmotic potential of the cell sap.

Answer 6

The movement of water through a semipermeable membrane is called osmosis.

Answer 7

osmosis

Answer 8

osmosis

Answer 9

osmosis