Ion Channels Flashcards
What is the difference between ion channels and transporters
Ion channels are passive, transporters are active
What is the basic gist of how ion channels work
Ligand attaches –> channel opens –> ions flood in –> change in membrane potential
How quickly do ion channels work
Very
Why do we care so much about ion channels
Ions mediate electrical signaling, they’re why the nervous system works
What are some means of passive transport
Simple diffusion
Facilitated diffusion
What is facilitated diffusion
The use of carriers or channels to help molecules cross the plasma membrane. NO energy used
Active transport -
Requires energy (ATP)
Moves things against gradient eg. ion pump
Do channels let any old ions in/out
No they are specific to an ion or group of ions
Concentration of Na+ inside/outside of cell
Low in, high out
Concentration of Ca2+ inside/outside of cell
Very low in, high out
What governs the movement of ions or what would make ions move in/out of a cell
The electrochemical gradient
Cells have a membrane potential at rest
Negative
An increase in membrane potential is called…
Depolarization
A decrease in membrane potential is called…
Hyperpolarization
What ions flow into the cell
Ca, Na
