Integral protein question - (Apr/19/2009 )

Note: This is not a homework question. I am just trying to understand the mechanism of integral proteins.

Question: We know integral proteins have nonpolar regions inside. But are integral proteins like channels (which have a tunnel inside) or are they like pumps or are they not hollow and cannot particles/molecules cannot move through them into/outside of the cell??????????????????? Can particles actually pass through them or not????????????

Research: My book and wiki seems to not explain this point (check wiki at http://en.wikipedia.org/wiki/Integral_membrane_protein ). So I turned here.

the term 'integral protein' covers so many things, I don't think it's possible to make such a blanket statement.

I know that it's possible for things to move through integrins (a subcategory of integral proteins). S. aureus invades epithelial cells through an integrin.

however....I can't answer this for all the cams and receptors this covers. they are all different, right?

okay. Thanks!