Supercritical Carbon Dioxide as a Solvent for Life

[Vaktus]

https://www.mdpi.com/2075-1729/4/3/331/htm

This paper explores the possibility for supercritical CO2 as a solvent for alien lifeforms, and the results are promising. Apparently, Enzymes in scCO2 would be more stable and less likely to produce side reactions than using water as a solvent. Enzymes would also would be able to keep "memories" of previous ligands bound to it when kept in scCO2.

 Could this be used in OA by a biosphere in a cytherian world? scCO2 does cover the surface of venus.

[Drashner1]

I'm also curious about this. Biology is not my area of focus, but whether as part of the T'oul'h ecology or a different world(s), this could be a cool, and potentially hard science, kind of thing.

Todd

[Vaktus]

I'm also curious about this. Biology is not my area of focus, but whether as part of the T'oul'h ecology or a different world(s), this could be a cool, and potentially hard science, kind of thing.

Todd

Recently, I have been kind of trying to compile a biosphere for many different worlds and keeping it in line with OA. I actually plan on putting some additions to the Muuh article for their biology and biosphere sometime soon.

[stevebowers]

This book should help
The Limits of Organic Life in Planetary Systems

especially this chapter
https://www.nap.edu/read/11919/chapter/8#76

Supercriticality in an environment does not, in itself, prohibit life. Some terran enzymes are known to be active in supercritical fluids.(30)-(32) Subsequent reviews can be found in Aaltonen and Rantakyla,(33) Kamat et al.,(34) and Aaltonen.(35) Although most of that work concerns supercritical carbon dioxide as the solvent, fluorinated hydrocarbons (HCF3) and simple alkanes (e.g., ethane, propane) have also been reported,(36) providing a formal demonstration that terran-derived proteins can function in these media. Any enzyme adapted to the supercritical media would undoubtedly be different from those used in the studies cited.

Organic chemists have been attracted for a variety of reasons to supercritical media as an environment for performing reactions. These reasons include, especially for CO2 and H2O, the environmental friendliness of the medium. The fact that supercritical fluids can be removed without a residue is an advantage. Other advantages include the solubility of gases within supercritical mixtures, the high diffusion rates, and the variable and adjustable density, solvent power, and dielectric constant of the medium. Ordinary gases, such as O2 and H2, are miscible with supercritical fluids, such as supercritical CO2. That property removes a limitation that is well known in standard liquids, including water, in which reactions are limited by the poor solubility of gases in the standard liquid. Table 6.1 shows some of the solvents studied.

Supercritical water is a key species in mineralogy, as well as in the commercial synthesis of crystalline inorganic species, including alpha-quartz and gemstones.(37) It has rarely been used in organic chemistry, although there are examples of its use for the oxidation of methane, the degradation of biopolymers, and the dehydration of alkenes.(38) Its high critical temperature (647 K) implies that many organic species are unstable in supercritical water. Nevertheless, some reactions are known.(39)

[Vaktus]

This book should help
The Limits of Organic Life in Planetary Systems

especially this chapter
https://www.nap.edu/read/11919/chapter/8#76

Supercriticality in an environment does not, in itself, prohibit life. Some terran enzymes are known to be active in supercritical fluids.(30)-(32) Subsequent reviews can be found in Aaltonen and Rantakyla,(33) Kamat et al.,(34) and Aaltonen.(35) Although most of that work concerns supercritical carbon dioxide as the solvent, fluorinated hydrocarbons (HCF3) and simple alkanes (e.g., ethane, propane) have also been reported,(36) providing a formal demonstration that terran-derived proteins can function in these media. Any enzyme adapted to the supercritical media would undoubtedly be different from those used in the studies cited.

Organic chemists have been attracted for a variety of reasons to supercritical media as an environment for performing reactions. These reasons include, especially for CO2 and H2O, the environmental friendliness of the medium. The fact that supercritical fluids can be removed without a residue is an advantage. Other advantages include the solubility of gases within supercritical mixtures, the high diffusion rates, and the variable and adjustable density, solvent power, and dielectric constant of the medium. Ordinary gases, such as O2 and H2, are miscible with supercritical fluids, such as supercritical CO2. That property removes a limitation that is well known in standard liquids, including water, in which reactions are limited by the poor solubility of gases in the standard liquid. Table 6.1 shows some of the solvents studied.

Supercritical water is a key species in mineralogy, as well as in the commercial synthesis of crystalline inorganic species, including alpha-quartz and gemstones.(37) It has rarely been used in organic chemistry, although there are examples of its use for the oxidation of methane, the degradation of biopolymers, and the dehydration of alkenes.(38) Its high critical temperature (647 K) implies that many organic species are unstable in supercritical water. Nevertheless, some reactions are known.(39)

Wow, thanks Steve! If it's true that it's dielectric, this is what our mitochondria uses to created compounds with lots of energy and communication between cells. Very useful for life indeed.


I've glossed over the chapter, and I find it interesting that silicon-based life could use liquid nitrogen as a solvent. I Looked at the reference for that section and apparently liquid nitrogen would work great with silanes and silinols. A silicon-based life vastly different from rheolithoids is possible.

Perhaps these life forms could live deep in cryovolcanos that spew liquid nitrogen and have quarts crystals in their cells to gain piezoelectricity from mechanical stress?