Thanks for making this helpful video! I wanted to clarify my understanding of the underlying physics so I would appreciate if you could correct any misconceptions I have. Statements such as "the chemical gradient pushes ions from regions of high concentration to low concentration" and "the electrical gradient pushes positive ions from regions of high positive charge to low positive charge" (paraphrasing) seem slightly imprecise (but I understand the didactic necessity for abstractions). It's not that there is a physical law that the chemical gradient pushes ions from regions of high concentration to low concentration but rather that, due to Brownian motion, it is more likely ON AVERAGE for particles to move in the direction of low particle concentration regions. Thus, the "force" exerted by the chemical gradient is just an emergent property of Brownian motion. It could happen by chance that a group of particles in one region move into a smaller region and become even more concentrated. But, over time, this situation is less likely to occur than diffusion. I would similarly press the abstraction of the electrical gradient exerting a "force" as well. Since the electromagnetic force extends infinitely (and decreases proportionally to 1/r^2), every charged particle exerts an electromagnetic force on every other charged particle (and this abstraction can be broken down further to the subatomic level but I don't think that's necessary for this topic). Thus, there is not an electrical gradient that pushes the K+ ions towards the other side of the membrane. Rather, as the concentration of K+ decreases in the bottom side (and the ratio of Cl- to K+ increases), there is, ON AVERAGE, a stronger electromagnetic force exerted on the top-side K+ ions toward the bottom side. But, this is not necessarily always the case. Let's imagine this situation: momentarily, due to Brownian motion, the remaining K+ ions in the bottom side moved right against the membrane (top of the bottom side) while the Cl- ions (all on the bottom side) moved to the bottom of the bottom side. At that moment, for any of the K+ ions in the top side, the y-component of the vector representing the summation of the forces of all the other molecules on that K+ ion would point away from the bottom side. When we say the electrical gradient "pushes" the K+ ions toward the bottom side it is rather that, on average (over time), the moment-to-moment average (over all the other ions) force exerted on each top side K+ ion points toward the bottom side (not directly toward it per se but I mean the summated forces vector's angle (where pointed exactly left = 0 radians and pointed exactly right = π radians) is more likely to be between π and 2π than 0 and π). I.e., much like the chemical gradient, the "force" exerted by the electrical gradient is an emergent property of many individual electromagnetic interactions. I just had the thought that perhaps the membrane has an effect on the electrical gradient somehow (negligibly?). Anyway, thank you for reading and I would love to hear any corrections to my understand of the underlying physics.
you're the BEST!! This is the most helpful way I have ever learned it and finally....got it :) I seriously love you, I watch you all the time when ever I need a bit more clearer explanation, keep it up, your making a difference, a huge difference!! :)
Something I think you should note is that when potassium is entering the cell in your example, the inside of the cell is potassium filled, (like is attracted to like), therefore it moves down it's concentration gradient (simple diffusion). If it were to enter a cell filled with hydrogen ions, it would require a channel protein and would move up it's concentration gradient because it's simply not attracted to the hydrogen ions. This is the electrochemical gradient...
characterize membrane needs permittivity, charge regulation with time, ion-ion, particle-membrane interactions only some membrane journals publish them numerical are few I suppose
Thank you so much, i never quite understood the electrochemical gradient before watching this. However, something is confusing me. What's the difference between the equilibrium potential and the resting potential?
*_...where does space, fit into your equations-when K⁺ gets across the membrane it's going to spread out (you implicated this already), but how far, does it go, equationally, and what-becomes of the chemical and electrical gradients and potentials near, far, and-farther..._*
Okay so I have been struggling with the fact that the overall concentration inside and outside the cell stays the same, bc of electrostatic force, yet if more ions leave/ enter the cell to reach their equilibrium potential, doesn't the concentration change at least for a short period of time? Like I get that it is pulled back into or out of the cell bc of electrostatic force, but still? I feel so dumb for not getting an intuition for this sorry
Hey Mr. Anderson, do you know if Tyler Dewitt is ever going to come back and make Chemistry videos for us? Or does he have some other work outside of RUclips he has to attend to?
assuming the equilibrium potential of K+ is -90mV, the K+channels would open up to release more k+ions outside the cell in order to bring up the resting membrane potential of "-110mV" closer to -90mV.
*_...p.s. Why is, the Nernst Equation-it obviously doesn't work at quantum levels where a single atom has a chemical gradient to cross the membrane, but once across it has the same to go back-so it's not-really a 'gradient' but maybe a 'half-gradient',-and why log when log 1 = 0, and log 0 = -∞, for that one lone atom ('wee-haw, giddy-app')..._*
In the start I would like to thank you very very much for this great doing and secondly I would to ask you 2 questions because I did not know how to solve them the first is why when we sleep for hours under cover in the bed we donot die what is the cause please sir answer me I need your help and the 2 question depend on a photo but I didnot know how to send it for you thank you again
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this video really helped me! the demonstration was simple and the commentary was very straightforward which really helps :)
you are the best teacher ive never had
Best video on youtube hands down, clear concise descriptions of mechanisms and how they function under differing environments...
I'm a UPenn student and find your videos so helpful. Thank you!
wIth full confusion from edx but now everything works out within 6 mins. Thank you so much
Best explanation I’ve ever been given 😮
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@@hussnainali2738 he has a different point of view, its in his profile name
I had the flu the day my professor was explaining this, this helped a bunch! I don't feel so behind anymore.
The best teacher who made me love physics
Thanks for making this helpful video! I wanted to clarify my understanding of the underlying physics so I would appreciate if you could correct any misconceptions I have.
Statements such as "the chemical gradient pushes ions from regions of high concentration to low concentration" and "the electrical gradient pushes positive ions from regions of high positive charge to low positive charge" (paraphrasing) seem slightly imprecise (but I understand the didactic necessity for abstractions). It's not that there is a physical law that the chemical gradient pushes ions from regions of high concentration to low concentration but rather that, due to Brownian motion, it is more likely ON AVERAGE for particles to move in the direction of low particle concentration regions. Thus, the "force" exerted by the chemical gradient is just an emergent property of Brownian motion. It could happen by chance that a group of particles in one region move into a smaller region and become even more concentrated. But, over time, this situation is less likely to occur than diffusion.
I would similarly press the abstraction of the electrical gradient exerting a "force" as well. Since the electromagnetic force extends infinitely (and decreases proportionally to 1/r^2), every charged particle exerts an electromagnetic force on every other charged particle (and this abstraction can be broken down further to the subatomic level but I don't think that's necessary for this topic). Thus, there is not an electrical gradient that pushes the K+ ions towards the other side of the membrane. Rather, as the concentration of K+ decreases in the bottom side (and the ratio of Cl- to K+ increases), there is, ON AVERAGE, a stronger electromagnetic force exerted on the top-side K+ ions toward the bottom side. But, this is not necessarily always the case. Let's imagine this situation: momentarily, due to Brownian motion, the remaining K+ ions in the bottom side moved right against the membrane (top of the bottom side) while the Cl- ions (all on the bottom side) moved to the bottom of the bottom side. At that moment, for any of the K+ ions in the top side, the y-component of the vector representing the summation of the forces of all the other molecules on that K+ ion would point away from the bottom side. When we say the electrical gradient "pushes" the K+ ions toward the bottom side it is rather that, on average (over time), the moment-to-moment average (over all the other ions) force exerted on each top side K+ ion points toward the bottom side (not directly toward it per se but I mean the summated forces vector's angle (where pointed exactly left = 0 radians and pointed exactly right = π radians) is more likely to be between π and 2π than 0 and π). I.e., much like the chemical gradient, the "force" exerted by the electrical gradient is an emergent property of many individual electromagnetic interactions.
I just had the thought that perhaps the membrane has an effect on the electrical gradient somehow (negligibly?). Anyway, thank you for reading and I would love to hear any corrections to my understand of the underlying physics.
Mr. Anderson, you're the best! We watch your videos all the time in biology and chemistry!
Thanks for explaining tough topics in simple words.... was helpful
you're the BEST!! This is the most helpful way I have ever learned it and finally....got it :) I seriously love you, I watch you all the time when ever I need a bit more clearer explanation, keep it up, your making a difference, a huge difference!! :)
thank you so much! it is the best explanation I've got so far about electrochemical gradient
Apparently my skull is quite thick, but that was refreshingly understandable. No matter how old you get science never stops being interesting.
This is the best site. Finally I found!
Why can RUclips videos from 5+ years ago always explain concepts so much better than my current professor.......
Thank you! I've been confused by this concept since grade 12 and I'm in my second year of uni right now
Sir please make a human physiology playlist. That would be amazing with you style of teaching.
thank you.
Thaks!!!! from Chile!!!
This was so helpful. So well explained and clear. Thank you
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Amazing video! Thanks a ton!!!
Thank you for the explanation, I finally got it, best ever!!!!❤️
Thank you for all your work!!
very conceptual presentation
thank you very much sir
I LIKE WHAT YOU GOT. GOOD JOB.
Something I think you should note is that when potassium is entering the cell in your example, the inside of the cell is potassium filled, (like is attracted to like), therefore it moves down it's concentration gradient (simple diffusion). If it were to enter a cell filled with hydrogen ions, it would require a channel protein and would move up it's concentration gradient because it's simply not attracted to the hydrogen ions. This is the electrochemical gradient...
Thank you so much for this, It was really helpful
This is great, really helped, Thank you!
Thank you. Great explanation.
This is a great video. Thank you
This was so helpful, thanks!
I’m confused as to why it’s 37/13 are we supposed to know how many on each side exactly or just a general ratio
characterize membrane needs permittivity, charge regulation with time, ion-ion, particle-membrane interactions only some membrane journals publish them numerical are few I suppose
Wow! Thank you so much for this!
Thank you so much, i never quite understood the electrochemical gradient before watching this. However, something is confusing me. What's the difference between the equilibrium potential and the resting potential?
Excellent explanation
*_...where does space, fit into your equations-when K⁺ gets across the membrane it's going to spread out (you implicated this already), but how far, does it go, equationally, and what-becomes of the chemical and electrical gradients and potentials near, far, and-farther..._*
When is an electrostatic gradient the strongest during the change in a neuron membrane potential?
thanks! that was really helpful; nice animations
how does that sand that dosent get wet in water work?
Nice presentation 👌
Thanks a looooooot .best explanation
Very helpful. Thank you!!
thanks really! best demonstration
does water molecules enter cells by electrochemical gradient?
That was very helpful, thanks alot
Okay so I have been struggling with the fact that the overall concentration inside and outside the cell stays the same, bc of electrostatic force, yet if more ions leave/ enter the cell to reach their equilibrium potential, doesn't the concentration change at least for a short period of time? Like I get that it is pulled back into or out of the cell bc of electrostatic force, but still? I feel so dumb for not getting an intuition for this sorry
HOT DANG! Finally makes sense 🙌
Fantastic , thank you 🙏
Hey Mr. Anderson, do you know if Tyler Dewitt is ever going to come back and make Chemistry videos for us? Or does he have some other work outside of RUclips he has to attend to?
If the cell membrane were hyperpolarized to a resting potential of -110 mV, what would be the effect on the potential opening of K+ channel?
assuming the equilibrium potential of K+ is -90mV, the K+channels would open up to release more k+ions outside the cell in order to bring up the resting membrane potential of "-110mV" closer to -90mV.
That was helpful, thanks!
*_...p.s. Why is, the Nernst Equation-it obviously doesn't work at quantum levels where a single atom has a chemical gradient to cross the membrane, but once across it has the same to go back-so it's not-really a 'gradient' but maybe a 'half-gradient',-and why log when log 1 = 0, and log 0 = -∞, for that one lone atom ('wee-haw, giddy-app')..._*
That was so useful.
Love your work sir! Can you upload a video on Krebs Cycle please?
you are great 💜
woow! great , thank you very much 🌸
Thankyou Sir really helpful.
Please I have multiple equations if possible to help me
mind BLOWN
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How can we have potential when all fluid compartments are electroneutral(anions= cations) ? Can anyone help!! So confusing
I could've saved myself the past 2 hrs of staring at my professor's slides (and still being confused) by just watching this 5 min. video. 🤦♀️
Yes that was very helpful
Thanks a lot
very helpful
Hey could you try this software? Pin Point: 'Circuit Solver' by Phasor Systems on Google Play.
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Thank you !
In the start I would like to thank you very very much for this great doing and secondly I would to ask you 2 questions because I did not know how to solve them the first is why when we sleep for hours under cover in the bed we donot die what is the cause please sir answer me I need your help and the 2 question depend on a photo but I didnot know how to send it for you
thank you again
do you still alive?
It was thank you very much 👍
You are amazing
why can't the chloride pass through
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really dont know how to thank u !
Hi