The importance of water for life

[curious_ocean]

Hi PF,
I'm teaching a college level introductory course about planet Earth and we are briefly discussing the importance of water for life. This is not covered in our textbook but I thought it was important to cover.

I found some good resources:
https://sitn.hms.harvard.edu/uncate...les-of-water-why-is-water-necessary-for-life/
https://www.khanacademy.org/science...d-hydrogen-bonding/a/hs-water-and-life-review
https://courses.lumenlearning.com/wm-nmbiology1/chapter/why-life-depends-on-water/

and I also found this in an online class about Oceanography:
"All life on Earth requires liquid water because water is a fantastic solvent; in fact, it is often called the universal solvent.

In addition, water has a phenomenal property of retaining heat and moderating temperature, so it is important for organisms to manage the heat within their structures.
Water also can suspend solids, so it can suspend wastes and nutrients and allow you to expel them from your cellular structure."

Can someone explain further what that last statement is about? Are wastes and nutrients necessarily solids? Is this a reference to the undissolved things that water can transport? (Hydrophobic substances vs. Hydrophilic?)

Thanks for your help!

 

[jim mcnamara]

I assume is referring to exocytosis - the process of moving waste out of a vacuole through the cell membrane and out into the surrounding medium. Molecules that do not pass through cells easily are sometimes accompanied by lipoproteins, which expedite things. Golgi bodies are active in secretion as well.

Wastes are not always solids.

You probably have shown students Brownian motion, which is a kind of "suspension" -- if that is what you are asking.

exocytosis and endocytosis -- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4880020/
Golgi apparatus -- https://www.ncbi.nlm.nih.gov/books/NBK9838/

 

[curious_ocean]

Thank you jim mcnamara! Is there are particular property of water that makes it special to be able to contribute to exocytosis/endocytosis?