Resting Membrane Potential LO4 Flashcards
Cells tissue and skin
Resting Membrane Potential
Potential energy (called voltage and measured in volts) that
exists across the plasma membrane resulting from
separating opposite charges by the plasma membrane
5 neg, 5 pos on inside and outside
ECF is slightly more positive than ICF
Ion concentrations and leakage channels
- ECF: higher concentration of Na+
- Na+ moves into cell through Na+ leakage channel
ICF: higher concentration of K+ - K+ moves out of cell through K+ leakage channels
- plasma membrane contains more K+
leakage channels than Na+
so more K+ ions move out of the cell than Na+ moves in.
Resting Membrane Potential generated by
the movement of potassium K+ ions from ICF
to ECF through K+
leakage channels in plasma membrane leaving
the outside of plasma membrane positive relative to the inside
Resting membrane potential maintained by
the active transport of ions using the carrier protein called the Na+/K+ ATPase pump
to stop the ions reaching equilibrium
the Na+ /K+ ATPase pump:
➢pumps out 3 Na+ ions
➢pumps in 2 K+ ions