The professor was lecturing in my class...and brought up this and assumed we all knew what it was and how it worked. But immediately after that class I had to go to another which is slightly far away so I couldn't stay back to ask him some questions.
Anways he stated that cell membrane potential is -60mV, due to the balance of diffusion and galvanic forces and proceeded to continue talking about action potentials and muscles.
So taking that and typing"cell membrane K+ Potential galvanic diffusion" in google(and reading tht textbook..but regretfully its a much more bio focused textbook that the professor really doesn't plan to use...i may even just return it to save myself 150$) yielded some info...As a result of that I've got this figured out:
Na+
===|=|===|=|===|=|=====| |==== lipid bilayer with some open K+channels
K+
Now because of the unequal concentrations on both sides (since Na+/K+atpase pumps use ATP to pump 3 Na+ into extracellular space, and take in 2K+ ions), there is a natural concentration gradients that are made. All Na+ gated channcel are closed, and MOST of the K+ channels are closed.
However, there are some ungated channels for K+ that allow passage, and theoretically given enough time K+ ions from the inside of the cellmembrane will have the concentrations on the inside and outside to equal eachother.
However, this is not the case, because we are only considering diffusion forces atplay. Up till here I feel comfortable, but this is where I start to get a little muddled, and would appreciate any help.
Now we need to also consider the opposing galvanic forces at work...for this i hard a harder time on google because it sat there talking about action potentials (as did the bio book...but that book really didn't use any maths, just vague graphs 😉)
Now the extracellular membrane surface has a LOT of Na+ so the charge is very positive, correct?
Now as K+ diffuses out of the occaisonal open membrane, it leaves the cytosol to the space outside the cell membrane, thus reducing a positive charge, and helping to create a negative charge build up on the inside.
But as we know, positive and negative charges attract eacother, so that negative charge on the inside of the cell is what HOLDS BACK the K+ from diffusing to the ousdie of the cell.
Thus the diffusive force that causes K+ to go out is balanced by a persistant negative charge holding back the K+. This potential is at roughly -60Mv if you measure the surface of the cell, since the outside is positive relative to the inner.
Can anyone help, correct, say it more clear for me? I need to know if I'm thinking this through correctly, because equations and modeling shall come in full force and week...and i don't want to be caught like a deer in the headlights of a car because I can't understand the basic interaction 😉
Anways he stated that cell membrane potential is -60mV, due to the balance of diffusion and galvanic forces and proceeded to continue talking about action potentials and muscles.
So taking that and typing"cell membrane K+ Potential galvanic diffusion" in google(and reading tht textbook..but regretfully its a much more bio focused textbook that the professor really doesn't plan to use...i may even just return it to save myself 150$) yielded some info...As a result of that I've got this figured out:
Na+
===|=|===|=|===|=|=====| |==== lipid bilayer with some open K+channels
K+
Now because of the unequal concentrations on both sides (since Na+/K+atpase pumps use ATP to pump 3 Na+ into extracellular space, and take in 2K+ ions), there is a natural concentration gradients that are made. All Na+ gated channcel are closed, and MOST of the K+ channels are closed.
However, there are some ungated channels for K+ that allow passage, and theoretically given enough time K+ ions from the inside of the cellmembrane will have the concentrations on the inside and outside to equal eachother.
However, this is not the case, because we are only considering diffusion forces atplay. Up till here I feel comfortable, but this is where I start to get a little muddled, and would appreciate any help.
Now we need to also consider the opposing galvanic forces at work...for this i hard a harder time on google because it sat there talking about action potentials (as did the bio book...but that book really didn't use any maths, just vague graphs 😉)
Now the extracellular membrane surface has a LOT of Na+ so the charge is very positive, correct?
Now as K+ diffuses out of the occaisonal open membrane, it leaves the cytosol to the space outside the cell membrane, thus reducing a positive charge, and helping to create a negative charge build up on the inside.
But as we know, positive and negative charges attract eacother, so that negative charge on the inside of the cell is what HOLDS BACK the K+ from diffusing to the ousdie of the cell.
Thus the diffusive force that causes K+ to go out is balanced by a persistant negative charge holding back the K+. This potential is at roughly -60Mv if you measure the surface of the cell, since the outside is positive relative to the inner.
Can anyone help, correct, say it more clear for me? I need to know if I'm thinking this through correctly, because equations and modeling shall come in full force and week...and i don't want to be caught like a deer in the headlights of a car because I can't understand the basic interaction 😉
