The Nernst Equation and Equilibrium Potentials in Physiology
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- Опубликовано: 3 окт 2024
- In this video, I introduce the Nernst Equation and explain how it can be used to calculate the equilibrium potential of an ion (with sample calculation). Additionally, I discuss the significance of the equilibrium potential and its role in determining net ionic movement.
LINKS TO RELATED RUclips VIDEOS:
-Ionic Basis of the Membrane Potential -- • The Membrane Potential...
-Ionic Basis of the Action Potential -- • The Action Potential: ... 
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Not every teacher can master the art of explaining complicated topics so easily... The fact that you did and you thought of posting it online is wonderful.. I wish you would keep publishing videos like this... We really need more teachers like you...
Thank you--I sincerely appreciate your kind words and encouragement. I'll be publishing more videos in the near future.
It's amazing to think how a handful of benevolent teachers like you sir can profoundly influence millions of students' education.
Thank you so much for this video! Just started my neurophysiology course and was asked about the Nernst equation. This was so thorough and I love the example you provided!
Thank you for the kind words! I really appreciate it. I'm glad this video was helpful Best of luck to you!
This video is very helpful for me! My teacher explained this to me twice and I couldn't wrap my head around it. The visual representation is what I needed! Thank you!
I'm glad this video was helpful! Thank you so much for the kind words!
i'm pissed that a free youtube video is better than professors that I paid ten of thousand of dollars to attend.
Thank you so much, I read about it but I still had some doubts about the subject, but watching your video cleaned up the issues for me! Life saver!
Mind blowing video!! Loved it.
I need to know about the Nernst equation from a chemical perspective. Yet this video has shown me so much detail and easy explanation that I couldn't understand with chemical videos. I love when the sciences mix, coexist and help each other. Thanks for the video
i am a indian and is currently attending high school and the lecture did help me a lot!!!! thanks\
thank you for the best video explanation Pete!
Thank you so much. The formula in the current guyton still uses the negative version this really made it clear to me now.
without the doubt the best explanation to Nersnt equation and its application I have heard to date. Thank you!
Thank you so much. Passing my exam because of you
sir your videos are too valuable to be explained , very Concise and top class representation .
Really we expect such more videos from you .
Mind-boggling clear explanation, greets from Taiwan ☺️
Very good video, you're an excellent teacher!
It took me 4 years to understand this concept. 4 years!
Could you help me understand it
You explained it amazingly (in a combination with the next video "the membrane potential")!!! Thank you sir!!
You are welcome! Thank you for the kind words!
best explanation for what the heck the electrical gradient is, have not found this in any other physiology explanation
I really appreciate the kind words. Thank you!
Thank you so much! I was so stuck on converting ln to log so I could never get the right mV. I finally understand this. You've been a great help!
Hi Janelle. I'm happy that it was helpful, and I really appreciate the positive comment. Thank you!
I love your way to explain which is so simple and conceptual.Keep it up.
Thank you!
valla türkçe anlamadıgım dersi ingilizcem kötüyken 10 dakikada anlattin helal olsun hocamm❤❤
This was SO HELPFUL!!!!!!
Glad this helped! Thank you for the positive comment!
Lecturer ❤❤is soo knowledgeable
Just a masterpiece❤
Please continue what u do this is unique educational content
Cleared up some questions I had after reading Hodgkin-Huxley in "Neural Dynamics". Great videos and clear explanations. Keep it up.
Thank you sos so sos much for this video- I know understand everything! God bless you
You are welcome! I am glad it was helpful!
I was asked this question during a physiology lecture and I got it wrong and none of my classmate could rescue me. Thanks for this wonderful , short video yet to the point!!
THANK YOU SIRRRR -- this saved me
Thank you so much I have a quiz about this tomorrow this really heleped
I hope your quiz went well! Thank you for the positive comment!
Thank you so much!! The explanation my professor provided was so confusing this really helped clear it up :))
I'm glad this video helped. Thank you for the kind words!
This video is amazing! Thank you so much!!
Very precise and straightfoward!! thank you for the amazing video
You're very welcome! Thank you!
I was so confused, but it actually makes sense now. Thank you, wish my professor thought like this!
Excellent content!
Thank you much love
Thanks for this nice refresher video!
Amazing video. Very well explained. Thank you so much
Thank you for the kind words Lauren. I really appreciate it!
thnx a lot this morning had 1hour lecture about it and couldn't understand till now in 10minutes u gave what my professor couldn't explain 😅
Clearly explained, thank you sincerely.
Glad it was helpful! Thank you for the positive comment!
This explanation is phenomenal!! Thank you!
Glad you think so! Thank you for the kind words!
thank you so much for this amazing video!!
Thank You King.
Faraday constant relates charge to number (moles), not mass. Excellent video zeroing in on the fundamental idea of balancing energy change of electrical versus chemical potentials.
Haha--good point! I think when I said "mass" in the video, I was speaking a little loosely for a moment. I'll see if I can squeeze in a correction/clarification in the video. Thank you!
Thank you for all of your videos! They're really very helpful!
You're very welcome! I'm glad they were helpful and I appreciate your positive comment!
Super helpful, thank you!
I'm happy that it was. Thank you for the positive comment!
Thanks, Awesome video.
This was great and exactly what I needed! Thank you
Thank you for the kind words!
you saved me thank you very much
Amazing
Thank you very much ! Your explanation is great.
I sincerely appreciate the kind words. Thank you!
Thanks so much I finally get it now!!
Glad I could help!
Another great video :) thanks!
Can you explain how the constants end up 61.5? No matter what I do, I can not seem to get that. When I multiply RxT and then divide by F I get... ((8.3)(310.3))/96500=0.026689
Hi Noah. No problem--the last steps are to convert from the natural log (ln) to the log base 10 (log), with the following step: 0.026689 x 2.3 ; and then convert from V to mV by multiplying that value by 1000. You should end up with ~61.5 mV (exact value will depend on how you round out your numbers). Hope that helps!
Thank you so much for the explanation! I had a qn: What does the sign mean? What is the difference between an electrochemical gradient of +80v vs -80v
Nice! Thanks for the perfect explanation on this concept :)
You're very welcome! Thank you for the kind words!
Wow! You are a great teacher.
Thank you! I appreciate it!
well explained
Great work!
This was really helpful!!! Thank you very much!!!
I'm glad it was helpful! Thank you so much for the positive comment!
Pete Hi. I was wondering if I could use a couple of your visuals in my Biophysics class. I will definitely give my students the link of this video. I absolutely loved the way you presented the subject.
Absolutely--I'm more than happy to share the images. I have them imbedded in a PowerPoint file. Email me at pcm@wsu.edu and I'll send them to you. Thank you for the kind words. I sincerely appreciate it!
Thank you this video was very beneficial for me
But I have a question. Actually a question just arose in my head when I was watching the video about where the direction of the ions will be if the voltage of the battery is equal to the membrane potential calculated in the video
Great Video!
Thank you!
This video was very helpful... Thank you..
I'm glad it was helpful! Thank you for the positive comment!
awesome
thanks! very well explained!
thank you sir, it was super helpful
great video!!
Thank u sir 🌍
Most welcome
Very grateful for this video- thank you so much. May Jesus bless you
Thank you Laura. I'm happy this video might have been a help to you, and I sincerely appreciate the kind words.
Great...👍
Thank you ❤
easily explained well done work😂
Thank you for this video!!
You are welcome! I'm glad it was helpful!
amazing!
Thank u sooooo much for this video 😄😄
The sad thing .. when your native language is not English, such a great video I wish I could understand it 100%
great thanks !!!!
Thank you so much
You're most welcome
Thank you sir
Thank you
Hmm. I am looking for Nernst-Planck Equation. Where the equation is:
J = -D*gradientC - (zF/RT)DC*gradient potential + Cv.
Really nice presentation. I would be happy if you clarify one of my question. Around 9 min, you are saying -80 mV. Can you please tell me what is negative volt mean? what is the significance of '-' and how it would be different if the result comes positive?
Thank you for the kind words! Voltage is a relative measure. By convention it is measured as the potential difference inside of the cell compared to outside the cell. This is similar to how blood pressure is the pressure difference inside the vasculature compared to the atmosphere (MAP ~= +100 mmHg). Or how atmospheric pressure is the pressure of the atmosphere compared to a vacuum (~= +760 mmHg at sea level). In an alternative universe, blood pressure could be expressed as the atmospheric pressure compared to inside the vasculature (i.e., MAP ~= -100mmHg). For voltage = -80mV, this is equivalent to having an 80 mV battery, but with the negative terminal oriented to inside the cell (positive terminal outside). Hope that helps!
@@PeteMeighan thank you so much for detailed answer.
Great video❤️
Thank you for the kind words!
how did you get 61.5 :((
Nice video, too helpful!
But why the ln can changes to log base 10?
god bless you
Why is the concentration ratio of only one type of ion relevant? Couldn't it be, for example, that some ion is more abundant inside the membrane than the outside, but some other particle is more abundant outside? This would make the concentration outside and inside equal in total, thus creating no diffusional force.
But the equation would think that it does in fact create a force, because it only accounted for the ion that is more concentrated inside.
Love this video!!! I just saw your bio online that you studied philosophy in undergrad. How did you go from philosophy to physiology? I'm pursuing graduate study in biomedical science now and my previous undergrad experience hails from the humanities, (English specifically). I'm curious if you would post about your transition and how you got into physiology from philosophy and what challenges you faced if any.
Thank you for the kind words and for your interest in my background! I was always interested in science, but couldn't stomach the way it's typically taught at the undergraduate level. I found the heavy emphasis on facts / memorization supremely boring. I fell in love with physiology because it is a vast, multi-disciplinary scientific arena that invites thought and emphasizes process, which can be understood by applying fundamental physical principles and molecular mechanisms. I firmly believe that a strong background in the humanities--which cultivates creativity, critical thinking and abstraction--is an excellent way to prepare for graduate-level study in the biomedical sciences. The main challenge, however, was having to maintain a single-minded focus on my graduate project. Furthermore, watching the diverse intellectual interests I once had whither away as I immersed myself in the narrow area of reality and thought I'd carved out for myself was a little depressing. However, I feel like I was able to compensate for that by becoming a bit of a generalist in my teaching and research. I believe that my background in philosophy/humanities made it easier for me to intellectually engage in areas not directly related to my research. Hope that helps! Let me know if you have any additional questions. Be well!
@@PeteMeighan I'm about to graduate with a bachelor's in philosophy and am trying to go into neuroscience. I'm finding the immense technicalities of organic chemistry difficult to grasp, to say the least. Your video is the only one so far that explained the Nernst equation clearly enough for me to understand, and stumbling across this comment about your background gave me some much-needed hope. Thanks for the video and for the boost.
Thank you for the positive comment--I enjoyed reading it! I can definitely relate to your experience in O-chem. It's easy to get discouraged as you are toiling away on pre-reqs that have little utility for your actual academic/intellectual goals. Keep going. Life gets better once you push thru that BS and are able to focus on the areas that interest you.
this is better than my 40k usd collage professors
What is the 'battery' in the case of the body?
Regarding the battery, is the positive electrode is the anode and the negative electrode the cathode? Because cations (e.g K+, Na+) move to the cathode, the cathode must be the negative electrode right?
Great video! but I have a question, If the equilibrium potential is -80, is the inside always negative?
Thank you so much! Most cells are only permeable to K+, so for them the answer is yes. However, some cells--such as neurons and muscle cells--can become (briefly) very permeable to Na+ (Eq. Potential approx +60mV) and/or Ca2+ (Eq. Potential approx +120mV). For these cells, the membrane potential can become inside positive. Not to plug my own videos, but if you are interested in seeing how that works, check out my video on Action Potentials ( ruclips.net/video/9xZAY28VcoI/видео.html ). Thank you again!
@@PeteMeighan Thankyou so much!
i am confused . when you calculatetd the equilibrium you found it -80mV and then you said the batter has to be >+80 why is it plus and what do we do when we find a positive equilibrium
When we consider membrane voltages, by convention it is described as the voltage inside the cell relative to the outside of the cell. Also by convention, when we consider the voltage of the battery it is described as the voltage of the positive terminal relative to the negative terminal. To reconcile this, you need to think of the voltage of the battery based on the orientation relative to the cell. In this example, with the negative terminal oriented inside, think of the battery as having a negative voltage.
quick question, why is -50 mv smaller rhan -80? when technically -50 is bigger, do we ignore the negative sign when comparing voltage?
Good question! Essentially that's the case. -80mV is an electrical gradient / membrane potential that is larger in magnitude than -50mV. The sign indicates the polarity of the electrical gradient (where, by convention, it is the voltage inside the cell compared to the outside). Hope that helps!
Please, what values of R, T and F are used to derive 61.5?
Hi great video. I'm doing a module in Bioelectricity at university which is based on the book bioelectricity: a quantitative approach. Just wondering what the best learning resources you've found for this field. Thanks
Thank you for the kind words! The main neurophysiology texts that I've leaned on over the years are: "Foundations of Cellular Neurophysiology" (Johnston and Wu); "Biophysics of Computation" (Koch); and Bertil Hille's classic "Ion Channels of Excitable Membranes"
Ηi, may I ask why dont you include the electrode standard potential in the Nernst equation ? Thank you in advance.
Any good derivation of this equation.