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Facilitated Diffusion question - (Dec/25/2008 )

Note: This is not a homework question. This is part of a study effort to prepare for a big upcoming test.

Question: Does Facilitated diffusion require a hydrophilic channel?????????? If so, then how are large hydrophobic (meaning nonpolar) molecules going to diffuse in (because they are large molecules, they cannot use simple diffusion to diffuse through the plasma membrane)??????????

Progress on this question: AP Biology by Deborah Goldberg says that "Facilitated diffusion requires a hydrophilic channel that will passively transport specific substances acros the membrane..." I got really confused here because then how are large hydrophobic (meaning nonpolar) molecules going to diffuse in (because they are large molecules, they cannot use simple diffusion to diffuse through the plasma membrane)?????????? I initially believed that facilitated diffusion had hydrophobic and hydrophilic channels. I searched on the web, but the websites don't really mention anything about whether the channels are hydrophobic or hydrophilic or both.

-thewax-

I dont think hydrophilic channel is part of facilitated diffusion. U should read in Textbook of Biochemistry: With Clinical Correlations
by Thomas M. Devlin (Editor) or Biochemistry by Stryer

-kent19-

I think you should pull up a basic biochem book.

Facilitated diffusion can be mediated by protein channel, it can also use transport proteins (that either open of close like gates, or even go through a flipping motion to transport their cargo).

-perneseblue-

Thanks for everyone who answered!!!!!!

But I found that yes, facilitated diffusion does require a hydrophilic channel.

-thewax-