In lecture today you talked about the protein ferritin carrying Fe, but in the notes you call the protein transferrin. Which is it?
I apologize for the mix up. The Fe binding protein I was talking about that enters the cell by RME is transferrin. Transferrin is the iron binding protein that carries Fe in the blood. Ferritin is a different (intracellular) Fe binding protein that stores extra intracellular iron. For some unknown reason I slipped up and switched them. 2/3/03. I have a couple of “silly” questions about Na+ & K+: Why is there a low concentration of Na+ but high K+ in the cell? what’s the difference between Na+ and K+ contributing to the cell or to our bodies? We get Na+ mostly from the table salt, right? but usually, where do we get K+ from? There are several kinds of “why” answers — how it happens, what good it does, and how this particular system evolved. How it happens (in this case) is a function of the protein pumps in the cell membrane — they pump Na+ out and K+ in at the expense of ATP. But why do cells operate that way? I can’t answer that one. It may have to do with the relative sizes and pro