5 ms·

I would speculate that they could. Pressure should be a lot less significant at the bacterial scale. Sperm whales can survive at the surface and deep ocean, a

I would speculate that they could. Pressure should be a lot less significant at the bacterial scale. Sperm whales can survive at the surface and deep ocean, and are fairly closely evolutionary related to us so the pressure resistance is probably coming from large scale morphological changes and not structural differences at the cellular level.

pfortuny 8y ago
Is pressure relevant to a molecular membrane? I mean: it is not a sheet of metal ee are talking about but a layer of proteins...
- gus_massa 8y ago
  The internal part is at the same pressure, so they probably cancel. I'm more worried about the level of oxygen disolved in the water, but IANAB.
- marmaduke 8y ago
  I’d guess pressure due to ionic concentrations is more relevant
- gilleain 8y ago
  A layer of lipid, really, although there are certainly proteins in the membrane. I've no idea about pressure adaptation, but a quick google gives this (open) paper that looks useful: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5487899/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5487899/ From the abstract: >Maintenance of the functionality of the membrane during changing environmental conditions relies on the cell’s potential to rapidly adjust the lipid composition of its membrane So in other words, bacteria at depth seem to use a particular mix of lipids in their membrane. Since things have to cross the membrane it makes sense to me that it has to be stiffer or less so at different pressures.
  - pfortuny 8y ago
    Thanks!
- HarryHirsch 8y ago
  Pressure does affect chemical equilibria, the canonical example is that above a certain pressure calcium carbonate actually becomes soluble. That's why you don't find hard-shelled organisms at the bottom of the ocean. Kinetics are affected, too, because the energy of transition states varies with the pressure. That said, they grew the bacteria from their samples at ambient pressure without problems.
  - stevespang 8y ago
    "Pressure does affect chemical equilibria". Hmmmm, so would two water splitting electrolysis cells require the same electrical inputs, one at atmosphere and one at challenger deep depth, both to split the exact same amount of water ?
  - pfortuny 8y ago
    Mmh, thanks for the info.

pfortuny 8y ago

Is pressure relevant to a molecular membrane? I mean: it is not a sheet of metal ee are talking about but a layer of proteins...

gus_massa 8y ago
The internal part is at the same pressure, so they probably cancel. I'm more worried about the level of oxygen disolved in the water, but IANAB.
marmaduke 8y ago
I’d guess pressure due to ionic concentrations is more relevant
gilleain 8y ago
A layer of lipid, really, although there are certainly proteins in the membrane. I've no idea about pressure adaptation, but a quick google gives this (open) paper that looks useful: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5487899/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5487899/ From the abstract: >Maintenance of the functionality of the membrane during changing environmental conditions relies on the cell’s potential to rapidly adjust the lipid composition of its membrane So in other words, bacteria at depth seem to use a particular mix of lipids in their membrane. Since things have to cross the membrane it makes sense to me that it has to be stiffer or less so at different pressures.
- pfortuny 8y ago
  Thanks!
HarryHirsch 8y ago
Pressure does affect chemical equilibria, the canonical example is that above a certain pressure calcium carbonate actually becomes soluble. That's why you don't find hard-shelled organisms at the bottom of the ocean. Kinetics are affected, too, because the energy of transition states varies with the pressure. That said, they grew the bacteria from their samples at ambient pressure without problems.
- stevespang 8y ago
  "Pressure does affect chemical equilibria". Hmmmm, so would two water splitting electrolysis cells require the same electrical inputs, one at atmosphere and one at challenger deep depth, both to split the exact same amount of water ?
- pfortuny 8y ago
  Mmh, thanks for the info.