Final answer:
The question involves the semipermeable nature of cell membranes, which allows potassium ions to pass more freely while typically blocking sodium ions,
Step-by-step explanation:
The student's question is concerned with the permeability of cell membranes to various ions, specifically K+ (potassium) and Na+ (sodium). Biological cell membranes are semipermeable, allowing certain substances to pass while blocking others.
The cell membrane's differential permeability to ions is crucial for maintaining the cell's electrochemical gradient. K+ (potassium) ions are more freely permittable due to the presence of specific channels and the membrane's properties, whereas Na+ (sodium) ions are typically blocked but can be transported by special proteins like the Na+/K+ transporter.
Due to this differential permeability and continuous diffusion of ions, a layer of positive charge develops on the exterior, and a negative charge develops on the interior, resulting in a voltage across the membrane, which is essential for processes such as action potentials in neurons. leading to a voltage across the membrane important for cell functions such as nerve impulses.