Here's why:
* Resting Membrane Potential: This refers to the electrical potential difference across the cell membrane when the cell is not actively signaling. It's typically negative inside the cell compared to the outside.
* Sodium-Potassium Pump: This active transport protein embedded in the cell membrane uses energy (ATP) to pump three sodium ions (Na+) out of the cell for every two potassium ions (K+) pumped in. This creates a concentration gradient with more sodium outside the cell and more potassium inside, contributing to the negative charge inside the cell.
* Maintaining the Gradient: The sodium-potassium pump continuously works to maintain this concentration gradient, which is essential for the resting membrane potential and the ability of the cell to generate action potentials (nerve impulses).
Let me know if you'd like more detail on how the sodium-potassium pump works!
