anatomy of the action potential

the membrane potential becomes more positive during [ ]

depolarization

the membrane potential becomes more negative during [ ]

hyperpolarization

current is defined as the movement of [ ] charge

positive

inward and outward current are defined as any [ ] charge in or out of a cell

positive

if chloride ions are moving into the cell, the current is described as ?

outward current

the driving force for current flow is the difference between the [ ] and the [ ]

membrane potential & reversal potential

a negative current is also known as an [ ]

inward current

[ ] is a larger determinant of current as opposed to number of channels

driving force

inward current causes [ ]

depolarization

outward current causes [ ]

hyperpolarization

[ ] is the definition for the membrane potential at which the current reverses for a particular channel type

reversal potential

glutamate binding directly to AMPA receptor channels allowing opening and influx of sodium ion is an example of a [ ]

ligand gated channel

in a [ ] molecules bind to the channel causing a conformational change, causing the channel to open

ligand-gated channel

in a [ ] channels change conformation by “feeling” the voltage difference across the membrane

voltage-gated channel

when the membrane potential nears -40mV, sodium channels opening is an example of a [ ]

voltage-gated channel

a [ ] is composed of 4 subunits or domain

voltage-gated channel

in a voltage gate channel domain there are [ ]

6 transmembrane segments

P loop between 5 & 6

transmembrane segment [ ] is intimately involved in gating; feeling charge from amino acids

S4 - four positively charged amino acids

transmembrane segments [ ] and [ ] chagne the conformation to permit flow through the flow

S5 and S6

low energy conformation is [ ]

closed

[ due to attractive forces with the negative charges in cell ]

positively charged amino acids

lysine, histidine, arginine

[ citruline / ornithine from urea cycle ]

stochastic process

something finishes first but the same thing also finishes last
[ one person with a 1000 clones running the Peachtree 10k ]

voltage gated channels are [ ] at hyperpolarized membrane potentials like -70mV even though the driving force is HUGE

not open