# osmosis v. facilitated diffusion

**URL:** <https://boards.straightdope.com/t/osmosis-v-facilitated-diffusion/643660>\
**Category:** Factual Questions\
**Created:** [December 11, 2012, 1:09am UTC](https://boards.straightdope.com/t/osmosis-v-facilitated-diffusion/643660 "2012-12-11T01:09:53Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![dauerbach](https://avatars.discourse-cdn.com/v4/letter/d/c2a13f/32.png) [@dauerbach](https://boards.straightdope.com/u/dauerbach)\
**Post date:** [December 11, 2012, 1:09am UTC](https://boards.straightdope.com/t/osmosis-v-facilitated-diffusion/643660/1 "2012-12-11T01:09:53Z")

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Is the passage of water between a cell and the environment osmosis or facilitated diffusion? Does the fact that aquaporins are used make it Facilitated diffusion.

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**Author:** ![dauerbach](https://avatars.discourse-cdn.com/v4/letter/d/c2a13f/32.png) [@dauerbach](https://boards.straightdope.com/u/dauerbach)\
**Post date:** [December 11, 2012, 1:14am UTC](https://boards.straightdope.com/t/osmosis-v-facilitated-diffusion/643660/2 "2012-12-11T01:14:05Z")

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And in a related question, what is the percentage of water in cytoplasm, for the purposes of osmotic gradient. Is 78% correct?

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**Author:** ![Speaker\_for\_the\_Dead](https://avatars.discourse-cdn.com/v4/letter/s/c77e96/32.png) [@Speaker\_for\_the\_Dead](https://boards.straightdope.com/u/Speaker_for_the_Dead)\
**Post date:** [December 12, 2012, 12:11am UTC](https://boards.straightdope.com/t/osmosis-v-facilitated-diffusion/643660/3 "2012-12-12T00:11:58Z")

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Osmosis.