How do charged particles move across membranes?

Answer 1

nonmediated
Charged particles like Na and K ions move across membranes through transport proteins. I think the specific transport protein you're probably looking for is the Sodium-Potassium Pump, though it may be known under other names.

My gr 12 Biology teacher (I live in Canada, if gr 12 sounds strange to you) showed us this really awesome video, which can be found at:

http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_the_sodium_potassium_pump_works.html

The sodium-potassium pump is a form of active transport. Its a lot easier to think of it in steps.

1. the protein has a high affinity for Na+, so cytoplasmic Na+ will bind to the protein.

2. This binding process stimulated the adding of a phosphate group (phosphorylation), by ATP. The energy from the ATP is enough to push the Na+ against its gradient.

3. the phosphorylation triggers the protein's changing shape. The shape change is accompanied with the the movement of Na+ against their gradient. The protein loses its high affinity for Na+ and they have now successfully moved across the gradient.

4. The new shape has a high affinity for K+. The K+ now bind to the protein. The binding of the K+ triggers the release of the phosphate group that changed the protein's shape in the first place.

5. With the phosphate gone, the protein reverts back to its original shape. Again, the shape change is accompanied with the movement of ions against their gradient; this time it's K+.

6. the old shape, as you may recall, has a high affinity for Na+ - it has lost its affinity for K+ and lets the ions go. These ions have now successfully crossed the membrane. As the protein has reverted to its old shape it is now available to bind to Na+ ions again, starting step 1 again. If you would like to continue, please go back to step 1. :)

Answer 2

Charged particles like Na and K ions move across membranes through transport proteins. I think the specific transport protein you're probably looking for is the Sodium-Potassium Pump, though it may be known under other names.

My grade 12 biology teacher (I live in Canada, if grade 12 sounds strange to you) showed us this really awesome video, which can be found at:

http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_the_sodium_potassium_pump_works.html

The sodium-potassium pump is a form of active transport. Its a lot easier to think of it in steps.

1. the protein has a high affinity for Na+, so cytoplasmic Na+ will bind to the protein.

2. This binding process is stimulated the adding of a phosphate group (phosphorylation), by ATP. The energy from the ATP is enough to push the Na+ against its gradient.

3. the phosphorylation triggers the protein's changing shape. The shape change is accompanied with the the movement of Na+ against their gradient. The protein loses its high affinity for Na+ and they have now successfully moved across the gradient.

4. The new shape has a high affinity for K+. The K+ now bind to the protein. The binding of the K+ triggers the release of the phosphate group that changed the protein's shape in the first place.

5. With the phosphate gone, the protein reverts back to its original shape. Again, the shape change is accompanied with the movement of ions against their gradient; this time it's K+.

6. The old shape, as you may recall, has a high affinity for Na+, thus it has lost its affinity for K+ and lets the ions go. These ions have now successfully crossed the membrane. As the protein has reverted to its old shape it is now available to bind to Na+ ions again, starting step 1 again. If you would like to continue, please go back to step 1. :)

Answer 3

Charged particles can cross membranes through ion channels or transporters that provide a specific pathway for them to move. They can move by simple diffusion through channels or be actively transported by pumps or carriers. The movement of charged particles across membranes is important for various cellular processes such as nerve conduction and muscle contraction.

Answer 4

1. Lipid Diffusion
2. Osmosis
3. Passive Transport
4. Active Transport
5. Vesicles

Answer 5

Charged particles cannot simply cross the plasma membrane. They use ion channels, such as a sodium potassium pump, to move across the membrane.

Answer 6

Through a specific protein channel.

Answer 7

Yes through a protein pump