Minor Contradiction Regarding Action Potentials

[jwnichols21]

Advertisement - Members don't see this ad

Hello,

Quick question:

Kaplan says: Na+ gates close first, and then K+ channels open
Cliffs says: Soon after the K+ gates open, the Na+ gates close

So which one is it? I would hate to miss this question on the test so I knew I had to ask. Thanks.

 

[knugget]

http://www.blackwellpublishing.com/matthews/channel.html
http://highered.mcgraw-hill.com/olc/dl/120107/anim0013.swf

Fast Na gates open then-> slow K gates open -> fast Na gates close while slow K gates take a while to close (hyperpolarization)

someone correct me if i'm wrong.

 

[FROGGBUSTER]

I think they're both correct. This is way more in-depth than is necessary for the DAT but basically the sodium channels have 2 gates.

Na+ gate #1 opens and Na+ ions rush in --> K+ channels open and K+ rushes out --> Na+ gate #2 closes, preventing Na+ from rushing in --> K+ keeps rushing in, leading to hyper-polarization --> Sodium-potassium pump restores concentrations and resting potential across membrane

One of the gates is called "activation gate" while the other is called "inactivation gate" (this is the one that closes after the first one).

 

[UCSD1984]

I think they're both correct. This is way more in-depth than is necessary for the DAT but basically the sodium channels have 2 gates.

Na+ gate #1 opens and Na+ ions rush in --> K+ channels open and K+ rushes out --> Na+ gate #2 closes, preventing Na+ from rushing in --> K+ keeps rushing in, leading to hyper-polarization --> Sodium-potassium pump restores concentrations and resting potential across membrane

One of the gates is called "activation gate" while the other is called "inactivation gate" (this is the one that closes after the first one).

This is how I understand it as well, and I think that's more than enough information.

 

[jwnichols21]

I think they're both correct. This is way more in-depth than is necessary for the DAT but basically the sodium channels have 2 gates.

Na+ gate #1 opens and Na+ ions rush in --> K+ channels open and K+ rushes out --> Na+ gate #2 closes, preventing Na+ from rushing in --> K+ keeps rushing in, leading to hyper-polarization --> Sodium-potassium pump restores concentrations and resting potential across membrane

One of the gates is called "activation gate" while the other is called "inactivation gate" (this is the one that closes after the first one).

You meant to say " K+ keeps rushing OUT," right?

Sorry, just trying to get this settled.

 

[FROGGBUSTER]

You meant to say " K+ keeps rushing OUT," right?

Sorry, just trying to get this settled.

Oops, yes that's what I meant.