Sodium-potassium pump

Question 1

Describe what happens in the sodium- potassium pump

Answer 1

The pump has high affinity for sodium ions inside the cell; binding occurs;
phosphorylation by ATP; conformation changes; affinity for sodium ions decreases; sodium ions released outside of the cell; potassium ions bind outside the cell; dephosphorylation; conformation changes; potassium ions taken into cell; affinity returns to start.

Question 2

What does the sodium potassium pump do?

Answer 2

The sodium-potassium pump transports ions against a steep concentration gradient using
energy directly from ATP hydrolysis

Question 3

How many sodium and potassium are transported into and out of the cell?

Answer 3

For each ATP hydrolysed, three sodium ions are transported out of the cell and two potassium ions are transported into the cell. This establishes both concentration gradients and an electrical gradient.