Inside and outside the cells, you've got these ions and proteins of various charges. And they're actually distributed differently from inside to outside. So for example, if I were to take your blood right now and measure,. which is extracellular? Yes, and measure the concentration of sodium. It'll be what? 142 millimolar. Inside the cell, you're going to find most of your potassium ions, which is K plus. But can they change depending on the pH environment so they're losing things? It's called the PKA, my friend. We can do an episode on that but not today.