how is ATP involved in maintaining the sodium and potassium gradiants across the cell membrane??

Question

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Answer 1

Cells (particularly neurons) maintain a charge gradient across their membranes by building up concentrations of potassium and sodium ions. In order to move ions from areas of low concentration to areas of high concentration (which is the reverse of what would naturally happen), the cell must expend energy in the form of ATP. This is called active transport.

The plasma membrane of neurons contains special transport proteins that move Na+ ions out of the cell and K+ ions in. Here's how it works:

1) The Na/K pump is originally situated so that it is "open" to the inside of the cell and "closed" to the outside. There are three active sites exposed that can hold sodium ions.

2) Three Na+ ions from the interior of the cell bind to the active sites.

3) An ATP molecule phosphorylates the protein (gives it a phosphate group), which causes a conformational change. The protein changes shapes so that its active sites are exposed to the outside of the cell and closed to the inside.

4) The protein releases the Na+ ions. At the same time, 2 K+ ions bind to special active sites. This causes the phosphate group on the inner part of the protein to be released.

5) Now that the protein is dephosphorylated, it returns to its original conformation and releases the potassium ions inside the cell. So, at the expense of 1 ATP, 3 sodium ions have been exported and 2 potassium ions have been imported. The cell's interior is now 1 unit more negative, and the membrane is slightly more polarized. This continues until the cell has reached its resting potential of about -70 milliVolts.

Answer 2

ATP components potential to the Na+/ok+ ATPase pump. The sodium-potassium pump keeps the sodium and potassium gradients throughout the time of a cellular membrane. The pump is a sort of energetic transport because of the fact Na+ and ok+ are being moved against their concentration gradients (from a community of low concentration to a community of severe concentration) and this demands potential.

Answer 3

There is a protein called the Sodium/Potassium ATPase which is used to maintain the gradient of these two ions across cells. The protein will bind to sodium molecules inside the cell and then transport them to the outside by the hydrolysis of ATP. Potassium will then bind to the protein, which is brought inside the cell to complete the cycle. Once potassium is brought inside the cell, sodium is then free to bind to the protein again and repeat the cycle.

The sodium/potassium ATPase (or Na+/K+ ATPase) is involved in keeping large amounts of sodium outside the cell (relative to the inside), and large amounts of potassium inside the cell (relative to the outside). This establishes concentration gradients for both of these cations.

Answer 4

ATP is required to pump these ions across the membrane from low to high concentration.