Which of the following ions has a typically higher concentration inside the cell vs. outside?

The ion that typically has a higher concentration inside the cell compared to outside is the Potassium ion (K+).

Here's a step-by-step explanation:

1. Cells maintain a specific concentration gradient of ions across their membrane. This is crucial for various cellular functions such as maintaining the cell's resting potential, enabling action potentials in neurons, and driving the transport of other substances across the cell membrane.

2. The concentration of different ions varies inside and outside the cell. For instance, sodium ions (Na+) and chloride ions (Cl-) are more concentrated outside the cell, while potassium ions (K+) and organic anions (A-) are more concentrated inside the cell.

3. This concentration gradient is maintained by the cell using active transport mechanisms, such as the sodium-potassium pump, which pumps two K+ ions into the cell for every three Na+ ions it pumps out.

4. Therefore, the concentration of K+ ions is typically higher inside the cell compared to outside.