006 Donnan Equilibrium and Driving Force

006 Donnan Equilibrium and Driving Force

Leslie Samuel IBTV, The Nervous System 72 Comments

Donnan Equilibrium? Driving Force? What in the world do those things mean? Well, you’re about to find out. In this video I explain the concept of Donnan equilibrium and show how that leads to the Driving Force that’s responsible for generating an Action Potential, otherwise known as the Nerve Impulse. If you want to know even more details about Donnan Equilibrium, check out my Notes on the Nervous System.

Comments 72

  1. mazas1991

    And i was wondering.i am confused on smthing.What is the exact difference between Nerst equation Goldmans equation and Donnan equilibrium?because i dont understand clearly what each one talks about.thanx in advance.

  2. InteractiveBiology

    @mazas1991

    I will be working on more episodes pretty soon, but will be stepping back and starting with basic stuff.

    To answer your question, the Nernst equation is the formula used to calculate the Equilibrium potential for an individual ion (e.g. sodium).

    Donnan Equilibrium is similar to the Equilibrium potential.

    Goldman’s equation takes all of the ions into consideration and allows you to calculate the membrane potential of the neuron.

    Hope that helps!

    Leslie

  3. mazas1991

    @InteractiveBiology thanx very much…yeap it did but i read so many stuff about it that i got confused a bit..if u can, leave an msn or fb or something so i can ask u online some questions that still confuse me..because i have an exam in 1 week so i would appreciate sooooooo much…so if u have time and will hit me up with a message or answer to this comment.thank you very very much in advance.

  4. mazas1991

    thanx very much…yeap it did but i read so many stuff about it that i got confused a bit..if u can, leave an msn or fb or something so i can ask u online some questions that still confuse me..because i have an exam in 1 week so i would appreciate sooooooo much…so if u have time and will hit me up with a message or answer to this comment.thank you very very much in advance.

  5. InteractiveBiology

    @mazas1991 The best way to contact me is to use the link in the description of the video. It goes to my Interactive Biology website. There’s also a link to my facebook page on that site.

    All the best!

  6. mazas1991

    And i was wondering.i am confused on smthing.What is the exact difference between Nerst equation Goldmans equation and Donnan equilibrium?because i dont understand clearly what each one talks about.thanx in advance.

  7. InteractiveBiology

    @mazas1991

    I will be working on more episodes pretty soon, but will be stepping back and starting with basic stuff.

    To answer your question, the Nernst equation is the formula used to calculate the Equilibrium potential for an individual ion (e.g. sodium).

    Donnan Equilibrium is similar to the Equilibrium potential.

    Goldman’s equation takes all of the ions into consideration and allows you to calculate the membrane potential of the neuron.

    Hope that helps!

    Leslie

  8. mazas1991

    thanx very much…yeap it did but i read so many stuff about it that i got confused a bit..if u can, leave an msn or fb or something so i can ask u online some questions that still confuse me..because i have an exam in 1 week so i would appreciate sooooooo much…so if u have time and will hit me up with a message or answer to this comment.thank you very very much in advance.

  9. InteractiveBiology

    The best way to contact me is to use the link in the description of the video. It goes to my Interactive Biology website. There’s also a link to my facebook page on that site.

    All the best!

  10. InteractiveBiology

    Yeah, depending on my time availability. Send me a message and we can go from there. I don’t post that info publicly on youtube for the fear of spam :)

  11. InteractiveBiology

    Like I said, send me a message from my website. Go to the site and click on the contact link. You can send any message from there

  12. Tapahtumahorisontti

    Correct me if I’m wrong but shouldn’t Donnan equilibrium require at least two permeable ions and one non-permeable anion on either side?

  13. ediniz101

    isnt sodium moving into the cell because of concentration gradient? and its being stopped by its charge potential?

  14. selenaddict

    Can someone explain me why we say that sodium is at is own equilibrium’??
    when we consider only K+ and Na+ we say that there s no equilibrium , coz we say that membrane potentiale isnt an equilibrium potential ..am i wrong??in fact in the membrane state of rest there s flow of Na+ trhought the membrane to the inner surface of the membrane..

  15. selenaddict

    Can someone explain me why we say that sodium is at is own equilibrium’??
    when we consider only K+ and Na+ we say that there s no equilibrium , coz we say that membrane potentiale isnt an equilibrium potential ..am i wrong??in fact in the membrane state of rest there s flow of Na+ trhought the membrane to the inner surface of the membrane..

  16. InteractiveBiology

    The statement I think I made was that the Membrane potential is at the Equilibrium potential for Sodium. Not 100% sure what you are asking though.

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  17. Lana

    You mentioned that the Na+ needs to reach a donnan equilibrium of 58MV, and when it is not near the resting membrane potential state of -50 to -80MV, the NA+ feels uncomfortable. Thus, causing sodium ions to rush into the cell. However, how does rushing into the cell make it “positive?” I thought the point of sodium to move into the cell was to become more comfortable, which meant reaching -50 to -80MV?

    Thank you in advance!

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