Lecture 2 Flashcards
resting membrane potential is determined by the _________ concentration gradient. WHY?
K+
because these channels are most permeable at rest
Nernst Potentials can be used to determine _________ ________________ and __________ of ion flow across the membrane.
driving force and direction
when the ____________ and _____________________ gradients are equal and opposite then the movement stops
electrical and chemical
what is the equation for the driving force?
DF= (Vm-Eion)
Action potential is a “___________ or ____________ response”
ALL OR NONE
action potential have same amplitude(…cell specific) that occurs exclusively in the ____________ of a neuron
axon
action potentials only occur if membrane potential passes a threshold (around ______)
-40 mV
action potential overall shape depends on ________________________________ expressed in the axon
kinetics of specific ion channels
be able to identify and explain the following terms on an action potential graph:
- hyperpolarization
- depolarization
- rising phase
- overshoot phase
- falling phase
- undershoot phase
- polarization
depolarization= more POSITIVE
polarization = more NEGATIVE
resting and action potentials arise from what?
differential permeability to ions
Na or K?
Which ion “jumps right out of bed” once the alarm goes off?
Na
The K channels do not inactivate but just slower and can open and close due to …..
getting closer to threshold and no voltage charge
what equation can you use to understand permeability changes associated with the action potential?
Goldman Hodgkin Katz
