Active transport must function continuously because __________.
- plasma membranes wear out
- not all membranes are amphiphilic
- facilitated transport opposes active transport
- diffusion is constantly moving solutes in opposite directions
How does the sodium-potassium pump make the interior of the cell negatively charged?
- by expelling anions
- by pulling in anions
- by expelling more cations than are taken in
- by taking in and expelling an equal number of cations
What is the combination of an electrical gradient and a concentration gradient called?
- potential gradient
- electrical potential
- concentration potential
- electrochemical gradient