Bernard Jenkins


  1. Thank u very much!u hv saved my days!!!!but may i kindly ask if water molecule is larger or smaller than electrolyes?

  2. Is salt good for our health in general?i remember salt is important to our body, but i dont remember how……😢

  3. Today I had a 4 hour lecture, this 6 min video was more informational.

  4. Isotonic can also be said equilibrium, which has more to do with pressure but I think it can be applied here as well.

  5. Khan you beast been trying to understand this instead of just memorize it for the longest time. This helped a lot!

  6. Thanks for making this sooooo easy. This really helped me get through my bio final.

  7. So having a hypotonic solution would INCREASE or DECREASE tonic pressure?

  8. You should have made the items on the inside of the cell, the yellow solute particles, a different shape than the yellow solute particles outside of the cell. The reason I say that is because the yellow particles on the outside must have at some point crossed the semi-permeable cell membrane in order to get inside the cell, but as you say, this is in fact, not the the case. They cannot pass through the cell membrane at all. Therefore, the yellow particles on the outside are not the same kinds of particles as the yellow particles on the inside. Therefore, they should have been drawn a different shape and color, say, a triangle in red for example to show that they are different from the particles on the outside of the cell (if you originally place them on the inside of the cell). If you don't, surely at some point, someone is going to ask why you say the yellow particles cannot pass through the cell membrane but in fact, they appear to have, since they are both inside and outside the cell, meaning that at some point, they must have crossed the cell membrane.

  9. So i would like to know
    In both asmosis and diffusion all of them represents the movement of water malecular or diffusion represents the movement of water and osmosis represents the movement of particles
    Please i need your answer any scientist can answer me!

  10. Thank you, this really helped me understand. Before this video I couldn't comprehend this!

  11. who else is here from a teacher suggesting this video to the class as a good video to watch in preparation for a test?

  12. I have a teacher who does not teach 😂 he leaves everything to us and expects us to succeed in his course. This really helped me in understanding this concept that took me a long time to try to figure out on my own. I have a test tomorrow and I think I'm screwed but this helped me at least a bit to boost up my mark 😂👏🏼

  13. In other words, water follows solutes.
    Hypotonic: there is a higher concentration of solutes outside of the cell (eg. rbc) and the water wants to follows the solutes. As a result, the cell will crenate or burst.
    Hypertonic: there is a higher concentration of solutes INSIDE the cell and the water will follow inside. As a result the cell is so full of water and solutes that the cell will burst like a ball. :p

  14. If there is a lower concentration of the yellow things then why did he draw more of them in the circle? The other cells have less yellow things so don't they have the lesser concentration of the yellow things.

  15. Here is a link to a video on a common lab on cell transport:

  16. I do not know why they have a black board to write on. I barley can see it. Weird. Content is nice, I can not even see it.

  17. God bless you guys what a nice concept you are building up for the students 👍👍👍 hats off to you

  18. this is awesome!!! Khan academy is a way better method of learning than actually goin to school. I have my biology exam tomorrow and just a few minutes before i had no clue what isotonic and hypertonic and everything meant because my teacher confused me. After watching this vid everything is clear and i'm pretty sure i'm going to nail the tonicity questions in the exam.

  19. Say, Khan, in the diagrams, i think it's better to draw the same amount of solute inside the cell for every scenario, hypo, iso, and hyper. generally, only the concentration of solute in the environment changes.

  20. why in 3rd case solute molecule outside the membrane lessen the amount of water coming in to the membrane

  21. are these normal processes for healthy cell?? or the cell dies if inside hypotonic or hypertonic solution?? how to make solution in my body isotonic?? does eating specific type of food causes these abnormal behavior?

  22. this is all clear. My only difficulty to approach Khan Academy videos is that they use black background. It makes it hard for me to watch.

  23. I started using Kahn when I was in 7th grade math before anyone really knew what it was. Now I’m starting my sophomore year of college with a rigorous 6 week biology course. I love these videos and how they’re made so simply

  24. I get it… It helps when I draw out the pictures and I understand it… But isn't the definition of osmosis the movement of water from a high concentrated area to a lower area? Therefore, shouldn't the first image on the left be water moving from the inside to the outside?…. Similarly, for the hypotonic solution you described (3rd image on the right), shouldn't water from the inside should be moving towards the outside (higher concentration solute to lower concentration solute)?…. I know I'm wrong but I don't understand why

  25. youre awesome dude! what took 40mins of confusion, took you 6mins of well explained things! thank you very much with what all u do!!

  26. Sat through a whole class lecture for this and it took 1:59 of this video to make fully grasp the whole topic!!

  27. Does the semi permeable wall allow only water molecules and water solutions to pass and no other material?

  28. There are different experiences between a teacher in school and a teacher who teaches in school

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