Lecture 3 - Electrophysiology of the Cell Membrane Flashcards
what is a chemical/concentration gradient?
the energy provided by the difference in concentration moving from a high concentration to a low concentration across a plasma membrane
what is an electrochemical gradient?
the energy associated with moving charged molecules across the membrane when a membrane potential exists (Na+, K+ and CI-)
what is the concentration of Na+ outside the cell?
high
what is the concentration of K+ outside the cell?
low
what is the concentration of Na+ inside the cell?
low
what is the concentration of K+ inside the cell?
high
what is the concentration of Cl- outside the cell?
high
what is the concentration of CI- inside the cell?
low
what is the number for resting membrane potential?
-70mV
what does the Z represent in nersts equation?
valence charge
e.g Na+ will have valence charge of +1
what is the potential difference across the cell membrane generated by?
principally generated by the Na+/K+ATPase
what does the Na+/K+ATPase pump in and out?
pumps out 3Na+ for every 2K+ in
what is the relationship between resting membrane potential and equilibrium potential?
RMP is largely an outward K+ mediated equilibrium potential modified by a much smaller inward equilibrium potential for Na+ ions
how is resting membrane potential maintained?
K+ and Na+ are moved against their concentration gradient by energy from ATP
what is the relationship between resting membrane potential and ATP?
ATP sets up the RMP for every cell but this can be changed by the use of other ions or the opening/closing of channels