Flashcards in Ion Channels and ECG Deck (10):
what molecules can permeate a phospholipid membrane?
gases, small uncharged polar molecules, sometimes water
what molecules cannot cross a phospholipid membrane without transporters?
large uncharged polar molecules, ions, charged polar molecules
what are some characteristics of protein transporters?
protein is specific for molecule transported
protein binding site/channel may open/close
protein conformational change required
what are energy sources for transporters?
ATP or concentration gradient
what cells is Na K ATPase present in?
how much of a cells ATP is used by Na K ATPase to establish ion gradients?
what does Na K ATPase transport and where?
Na from cytosol to extracellular space
K from extracellular space to cytosol
what are values of Km required to pick up a ligand?
Km lower than ligand conc.
what are values of Km required to drop off a ligand?
Km higher than ligand conc.