Passive Transport

Posted by Professor Cram in Cell Membranes

Passive Transport

Passive transport is the cellular process of moving molecules and other substances across membranes.

Passive transport differs from active transport in that it does not involve any chemical energy. Rather, passive transport relies on the innate permeability of the cell membrane and its component proteins and lipids.

There are four main types of passive transport:

Passive Transport Video


Diffusion is the overall movement of material from an area of higher concentration to an area of lower concentration.

The difference in concentration between the two areas is called the concentration gradient; diffusion tends to continue until the concentration gradient is gone.

Once this happens, material still tends to move between the areas but with no net gain for one side or the other.

In the human body, waste products are removed from the bloodstream in the kidneys via dialysis, an example of diffusion. (Learn more about Diffusion Through A Membrane.)

Facilitated Diffusion

Facilitated diffusion is the carrier-mediated transport of large molecules through the cell membrane using transport proteins embedded within the cell membrane.These molecules would otherwise not be able to breach the cell membrane, but the transport proteins effectively “transport” them through.

This process is still diffusion, however, so the concept of the molecules moving from a higher concentration (outside the cell) to a lower concentration (inside the cell) without utilizing any chemical energy still applies.

The exchange of oxygen and carbon dioxide in the alveoli of the lungs is an example of facilitated diffusion. (Learn more about Membrane Proteins.)


In biological terms, osmosis is the diffusion of water though a membrane to a region with a lower concentration of water. (Learn more about Osmosis in a Plant Cell and Osmosis in an Animal Cell.)


Filtration is the movement of solute molecules and water across a membrane by normal cardiovascular pressure. The size of the membrane pores dictate the molecules that may pass.

Some functions of the liver and kidneys are based upon filtration.



28 Responses to “Passive Transport”

  1. red says:

    my fav site

  2. Megha says:

    Nice…got a greate help…:).

  3. izzi says:

    what? O_O

  4. says:

    Thank you. Good post. I think it’s really useful
    I’m going to come back

  5. Henry Crummedyo says:

    Hiya brilliant content many thanks keep up the great job :x

  6. David Brown says:

    Great blog! I enjoyed reading it!

  7. lachu says:

    it is so good.

  8. whey protein optimum says:

    I like the valuable info you provide in your articles. I will bookmark
    your blog and check again here frequently. I am quite sure I will learn plenty of new
    stuff right here! Good luck for the next!

  9. Malexi says:

    The videos are very helpful. I very much apretiated.

  10. Buy 1285 Muscle says:

    The potential benefits: it raises metabolic rate, helps remove abdominal fat, boosts muscle growth, reduces resistance to insulin,
    strengthens the immune system and lowers food allergy reactions.
    The shoulder and hip airbags for the EP — 30005 have been removed compared to the 30006 and 30007.
    Also surprising was that stimulative music and silence showed absolutely no
    difference in strength gains or loss.

  11. Tyler says:


  12. Antione Lefave says:

    Rail travel, is reemerging, as one of the most efficient and effective methods, of addressing many of the challenges facing society in the 21st Century. Today train technology, increasingly allows the rail industry, to play a leading role in moving big numbers of people and freight, across often large distances, with a reduced impact of the Earth’s environmental status.

  13. says:

    If you are prone to blisters, then taping your feet in troublesome areas with
    zinc oxide tape is advisable. Doing these physical exercises will help reduce your cravings and the stress associated with them by refocusing
    your consideration on the breathing exercise, not your cravings.
    Body mass Index is a Nokia fitness calculator app that lets
    you calculate, as the title suggests, your body mass index (BMI).

  14. Mafalda Jasper says:

    I know this if off topic but I’m looking into starting my own weblog and was wondering what all is needed to get setup? I’m assuming having a blog like yours would cost a pretty penny? I’m not very internet savvy so I’m not 100% certain. Any tips or advice would be greatly appreciated. Thank you

  15. Health Junkies says:

    It always fascinates me how the human body is such a well refined chemical machine.

  16. says:

    These electronic cigarettes include a lots of complicated parts
    just like the atomizer, the cartridge along with a energy supply, which may be
    the cause that they will be usually high priced.

    t low tar residue or light cigarettes, though they perform entirely on a different scientific
    application. Just ahead of the advent of electric
    cigarettes, quitting the habit of smoking never was a simple work for smokers.

  17. Daryl says:

    Do you know that you can copy articles from other sites to your site and they will pass copyscape test and google will see them as unique?

    I know one cool tool that will help you to do that, just search in google – rewriter creates an unique article in a minute

  18. Malcolm Foglio says:

    naturally like your website however you need to test the spelling on several of your posts. Several of them are rife with spelling problems and I in finding it very troublesome to inform the truth nevertheless I will certainly come again again.

  19. Robby Dewing says:

    This will be a great web page, might you be interested in doing an interview about how you developed it? If so e-mail me!

  20. Shawnda Brentano says:

    Can I just say what a reduction to search out someone who really is aware of what theyre talking about on the internet. You definitely know how you can convey an issue to gentle and make it important. Extra people have to read this and perceive this side of the story. I cant believe youre not more fashionable because you definitely have the gift.

  21. Catrice Stoebner says:

    The subsequent time I learn a blog, I hope that it doesnt disappoint me as a lot as this one. I mean, I know it was my choice to learn, but I really thought youd have one thing attention-grabbing to say. All I hear is a bunch of whining about one thing that you could possibly fix in the event you werent too busy in search of attention.

  22. Felipe Bushby says:

    some really interesting points you have written.

  23. Natalia Cutrell says:

    I conceive this site has very excellent pent subject material blog posts.

  24. Kim Rumrill says:

    With havin so much written content do you ever run into any problems of plagorism or copyright violation? My blog has a lot of completely unique content I’ve either authored myself or outsourced but it looks like a lot of it is popping it up all over the internet without my permission. Do you know any ways to help stop content from being ripped off? I’d really appreciate it.

  25. Arlen Dapoz says:

    I do enjoy the way you have presented this particular situation and it really does supply me a lot of fodder for thought. Nevertheless, through just what I have observed, I simply wish as the actual feedback pile on that men and women remain on issue and don’t embark upon a tirade regarding the news du jour. Anyway, thank you for this fantastic piece and while I do not really go along with it in totality, I respect your viewpoint.

  26. § Spirit § says:

    I loved it! Thank you so much!

  27. Turtleboy1234 says:

    I like turtles

  28. BlackWolfRaider says:

    this really helps me

Leave a Reply