Biology-Online • View topic - Action Potential

Join for Free!
121739 members

Action Potential

For discussing the functions of different structures of all organisms.

Moderator: BioTeam

Action Potential

Postby sugars888 » Thu Sep 29, 2011 5:12 am


If the density of K+ channels in the axon was increased by 50%, which of the following statements would be true?

1. The amplitude of the action potential would be reduced by 50%
2. The falling phase would be more steep
3. The falling phase would have a steeper slope
4. The amplitude of the action potential would be increased by 50%
5. The relative refractory period would be affected
6. The threshold for action potential generation would be more negative (hyperpolarized)
7. The nadir (most negative point) of the undershoot phase (after hyperpolarization) would be more negative
8. The 'width' of the action action potential would be increased

I said that 2,3 and 7 are correct. 7 is correct because K+ in the cell is high which makes the inside of the cell more positve more K+ would want to go out thus cell becomes more negative. if more K+ are leaving the cell the slope would be steeper. Is this reasoning correct? Also am not sure about the rest can you please explain it to me
Posts: 1
Joined: Thu Sep 29, 2011 5:07 am

Postby merv » Sun Oct 02, 2011 9:35 pm

this aint genetics- try posting in a biochemisty or physiology forum.
Death Adder
Death Adder
Posts: 58
Joined: Sun Oct 02, 2011 2:05 pm

Postby JackBean » Mon Nov 28, 2011 8:15 am


Cis or trans? That's what matters.
User avatar
Inland Taipan
Inland Taipan
Posts: 5694
Joined: Mon Sep 14, 2009 7:12 pm

Postby david23 » Fri Jun 29, 2012 9:55 pm

Your reasoning is right, the number of channels does control the slope, hence 2 and 3, they both sound the same. 7 isnt right. The concept of more negative or not is an inherent property of the channel and cell. it would not be changed by having more channels.
Posts: 430
Joined: Thu May 03, 2007 8:15 am

Postby asdmf » Sat Jul 28, 2012 7:12 am

i am satisfy with ur post .ur concept is more nagetive and inherent property of cell.
Posts: 1
Joined: Sat Jul 28, 2012 6:55 am

Postby tmbirkhead » Sun Sep 23, 2012 5:31 am

I'm not sure exactly what number 7 is asking, but the cell membrane potential (with respect to the inside of the cell) would become more negative as read on a microscopic voltmeter.
If I understand it as talking about the cell membrane potential then number 7 would be correct.

Mike's Online Biology: MOB University
Posts: 6
Joined: Sat Sep 22, 2012 7:41 am

Return to Physiology

Who is online

Users browsing this forum: No registered users and 0 guests