[Campbell Biology P.1119] Based on Table 48.1 and the description of the sodium-potassium pum... | Practice Question

Based on Table 48.1 and the description of the sodium-potassium pump, which statement correctly describes the ion concentrations and pump action?

  • A: Intracellular K+ concentration is 5 mM, and the pump moves K+ out of the cell.
  • B: Extracellular Na+ concentration is 15 mM, and the pump moves Na+ into the cell.
  • C: The sodium-potassium pump transports 3 Na+ ions out of the cell for every 2 K+ ions transported in.
  • D: Chloride ions are actively pumped out of the cell to maintain their high extracellular concentration.

Explanation

Table 48.1 shows the ion concentrations, with high K+ inside and high Na+ outside. The text explicitly states that the sodium-potassium pump transports 'three Na+ out of the cell for every two K+ that it transports in' Figure 48.6 , using ATP to maintain these gradients.