Question

How could the charge inside neuron cell be negative when $K^{+}$ ions are inside?

• A. High concentration of ${Na}^{+}$ ions outside cell
• B. Low concentration of $K^{+}$ ions inside cell
• C. Nucleic acid molecules inside cell

Answer 1

The correct option is C

Nucleic acid molecules inside cell

In addition to the $K^{+}$ ions, negatively charged protein and nucleic acid molecules are also present inside the cell. This results in a overall negative charge inside the cell. The final membrane potential depends on the permeability of the membrane to these ions.