What is the significance of the sodium-potassium pump?

• A. It speeds up nerve impulses
• B. It maintains the electrochemical gradient
• C. It alters cell size
• D. It synthesizes proteins

Answer: (B)

The sodium-potassium pump is crucial for maintaining the electrochemical gradient across the plasma membrane of cells, which is essential for various physiological functions. By actively transporting sodium ions out of the cell and potassium ions into the cell, it creates a difference in charge between the inside and outside of the cell, known as the membrane potential. This gradient is vital for processes such as nerve impulse transmission, muscle contraction, and the regulation of cellular volume.

Maintaining this gradient allows for the proper functioning of excitable tissues, enables cells to return to resting potential after an action potential, and supports metabolic processes. The pump operates continuously, consuming ATP to transport these ions against their concentration gradients, thus ensuring that the electrochemical environment is favorable for cellular activities.