Final answer:
The statement that potassium ions (K+) move opposite to sodium ions (Na+) is false. Potassium is actively transported into the cell, while sodium is transported out of the cell via the sodium-potassium pump.
Step-by-step explanation:
The student's question asks whether the ion moving in the opposite direction to sodium (Na+) is potassium (K+). The correct answer is false. The sodium-potassium pump actively transports three sodium ions out of the cell for every two potassium ions it pumps into the cell. As a result, potassium ions (K+) move into the cell, while sodium ions (Na+) are being moved out of the cell.
In the resting state, cells have a higher concentration of sodium ions outside and a higher concentration of potassium ions inside. Sodium and potassium ions move across the cell membrane through different mechanisms: sodium ions tend to move into the cell spontaneously (passive transport), while the sodium-potassium pump uses energy in the form of ATP to move potassium ions into the cell and sodium ions out of the cell, which is an example of active transport.
Therefore, the movement of potassium (K+) is not in the opposite direction of sodium (Na+); instead, they are both moved by different mechanisms, and the sodium-potassium pump is responsible for maintaining the concentration gradients of both ions.