When cell media becomes "used up", it acidifies - (Sep/18/2013 )

What is the source of these extracellular protons?

As with any living tissue, cellular respiration (glycolysis and oxidative metabolism) generates protons that can reduce the pH of cell media. It is the same as a respiring tissue within a living organism; however, a circulatory system is absent to replenish the media.

*On a side note. Pour bleach into your media and this will demonstrate that H+ ions are responsible for your pH shift. I do not know why I get such a thrill by doing that.

jerryshelly1 on Wed Sep 18 20:07:57 2013 said:

As with any living tissue, cellular respiration (glycolysis and oxidative metabolism) generates protons that can reduce the pH of cell media. It is the same as a respiring tissue within a living organism; however, a circulatory system is absent to replenish the media.

 

*On a side note. Pour bleach into your media and this will demonstrate that H+ ions are responsible for your pH shift. I do not know why I get such a thrill by doing that.

 

 

THanks for the response.  Do you know know what step of cellular respiration specifically generates protons?  Would this be due to the protons generated on the cytoplasmic side of oxidative phosphorylation that are released into the media during cell lysis?

Go review Glycolysis and the Krebs cycle and look for any enzyme with the work "dehyrogenase" in it.  This will show you where the protons are being generated. I am not sure if I understand the second question. My only knowledge on that would be that protons are released into the "actual media" due to symport and antiport for the use of bringing in the nutrients that are present in your DMEM (or other media). This is the energy that is required for specific uptake of some of your nutrients.

This is as much as I can elaborate without reviewing the relevant literature.

Hope this helps.