Is this a new thought? Life from liquid

[SanityDeprivedLunatic]

Has anyone else thought about Life without water? Does anyone else think it is possible for there to be life on a planet with massive amounts of a liquid such as, say, Mercury? Not really sure how to explain my question more than that. I mean, all elements have the potential to go through the same states of matter, so could different kinds of life spring up from a planet covered in liquid Mercury?

[Moontanman]

Has anyone else thought about Life without water? Does anyone else think it is possible for there to be life on a planet with massive amounts of a liquid such as, say, Mercury? Not really sure how to explain my question more than that. I mean, all elements have the potential to go through the same states of matter, so could different kinds of life spring up from a planet covered in liquid Mercury?

 

Mercury is not a particularly good solvent but there are other possibilities from liquid ammonia to liquid methane to concentrated sulfuric acid :Guns:

 

ALTERNATIVE FORMS OF LIFE: entries in the Internet Encyclopedia of Science

 

boron-based life

[HydrogenBond]

One advantage water based life has is one of the final products of metabolism is H2O. This allows aqueous life to to get the most energy out of its reduced food.

 

If we had life forming in NH3, for example, if we stopped metabolism at the solvent NH3, there is little energy for life, since the energy difference between -CH2- and NH3 is low. If we go all the way to H2O, then those life forms will digest their NH3 solvent and turn it into water. It is then a matter of time until H2O life takes over due to its energy and stability advantages. The water solvent will hold up.

[SanityDeprivedLunatic]

well, what would an ammonia based life form look like? How much different would it be from water based life?

[Rade]

well, what would an ammonia based life form look like? How much different would it be from water based life?

From this Wiki link:

 

Hypothetical types of biochemistry - Wikipedia, the free encyclopedia

 

is given this information about possible life in liquid ammonia:

 

Ammonia

 

Ammonia is perhaps the most commonly proposed alternative. Numerous chemical reactions are possible in an ammonia solution, and liquid ammonia has some chemical similarities with water. Ammonia can dissolve most organic molecules at least as well as water does, and in addition it is capable of dissolving many elemental metals. Given this set of chemical properties it has been theorized that ammonia-based life forms might be possible.

 

However, ammonia has some problems as a basis for life. The hydrogen bonds between ammonia molecules are weaker than those in water, causing ammonia's heat of vaporization to be half that of water, its surface tension to be three times smaller, and reducing its ability to concentrate non-polar molecules through a hydrophobic effect. For these reasons, some members of the scientific community question how well ammonia could hold prebiotic molecules together to allow the emergence of a self-reproducing system. Ammonia is also flammable and can be oxidized and could not exist sustainably in a biosphere that oxidizes it. It would, however, be stable in a reducing environment.

 

A biosphere based on ammonia would likely exist at temperatures or air pressures that are extremely unusual for terrestrial life. Terrestrial life usually exists within the melting point and boiling point of water at normal pressure, between 0 °C (273 K) and 100 °C (373 K); at normal pressure ammonia's melting and boiling points are between −78 °C (195 K) and −33 °C (240 K). Such extremely cold temperatures create problems, as they slow biochemical reactions tremendously and may cause biochemical precipitation out of solution due to high melting points. Ammonia could be a liquid at normal temperatures, but at much higher pressures; for example, at 60 atm, ammonia melts at −77 °C (196 K) and boils at 98 °C (371 K).

 

Ammonia and ammonia-water mixtures remain liquid at temperatures far below the freezing point of pure water, so such biochemistries might be well suited to planets and moons orbiting outside the water-based habitability zone. Such conditions could exist, for example, under the surface of Saturn's largest moon Titan.[13]

[HydrogenBond]

Life is more than replication and synthesis, it also requires metabolism to generate the energy that drives the replication and synthesis. There are energy problems using ammonia as the continuous phase, since the continuous phase of life also defines the floor for its energetics.

 

If you look at aqueous life, water is a product and reactant in many important reactions, such as metabolism, the synthesis or depolymerization of proteins. It is also involved in ATP --ADP. Water also generates the pH effects, which is critical to other reactions.The floor molecule has to be very versatile. It is not just throw the bio-materials in anything, but that anything needs to be useful everywhere.

 

Water is the most anomalous chemical compound in nature. Water does not play by rules the other chemicals of nature, such as ammonia, need to play by. It departs in 67 different ways. For example;

With increasing pressure, cold water molecules move faster but hot water molecules move slower.

 

Anomalous properties of water

 

If you need a wild card solvent that can participating in all aspects of life, and which does not have to play by the rules, you hand off to H2O. The goal of life was to turn inanimate matter into animate. Nature called upon its wild card molecule.

[Qfwfq]

The goal of life was to turn inanimate matter into animate. Nature called upon its wild card molecule.

Yeah Pangloss would definitely agree with that. He'd say: How else could the human nose have been so perfectly formed to bear spectacles...

[HydrogenBond]

There are a few places where the impact of the water is easier to see. For example, if you look at the hydrogen bonding between the base pairs of the DNA double helix, there are more H capable of hydrogen bonding that the DNA uses. For example, in the pic below, notice both guanine and cytosine both have an extra H (bottom and top, respectively) These extra hydrogen are used to form a double helix of water that is intertwined within the DNA. The extra H has a selective advantage via this water association.

 

Beyond the quadruple aqueous/DNA helix, we also have water that is associated with the DNA surfaces. Water can form up to four hydrogen bonds and therefore can connect in extensive networks, with the DNA offering a scaffolding all the way down to inside the DNA double helix. This allows the water to transmit information from inside the base pairing to the surface of the DNA, allowing substrate recognition of base pairs.

 

Enzymes carry their own water both internally and externally. If the enzyme-DNA water adds properly, we get energy from the combined water to assist dynamics. If the water does not add up properly, this will take way energy, lowering selectivity.

 

Since water is the majority component in a cell, from 70-90% by mass, the energetics of the water is an important variable, with nature preferring lowest energy and higher entropy within the water. Some random choices violate these natural laws, and are far less likely to persist.

 

For example, if the DNA or template material was purely organic, without hydrophilic groups, the lowest energy within the water would need to ball up the genetic material rendering it hard to react. Nature will eliminate all such as these as being a persistent template. The template has to be able to interact with the water. Allowing a double helix of water makes DNA and RNA perfect, since this is the give and take needed. We don't want our template too acquiescent, or its will lack potential to be a template. Nor do we wish to push to hard or the water will push it into a ball so it can't do anything. The proper balance was ideal defaulting to DNA and RNA.

 

If you look at RNA versus DNA, the DNA has more reduction, for example in the sugar group. Any form of reduction will increase surface tension in water; increases the aqueous energy. The DNA pushes against the water and water pushes back by making the DNA a double helix to avoid the reduction. The RNA, by pushing less is given a little more freedom; either a single or double helix. We could design a modification of RNA, with even less reduction potential, but water would make it more like a wet noodle, lacking the spunk to be a good template material. DNA and RNA are just right. (this template is too soft, this template is too hard, this template is just right; Goldilocks of evolution.

Edited August 12, 2010 by HydrogenBond

[maikeru]

 

Ammonia and ammonia-water mixtures remain liquid at temperatures far below the freezing point of pure water, so such biochemistries might be well suited to planets and moons orbiting outside the water-based habitability zone. Such conditions could exist, for example, under the surface of Saturn's largest moon Titan.[13]

 

Although a little off-topic, this is something I've seriously wondered about with the "liquid" moons of Jupiter and Saturn.

[paigetheoracle]

Excuse me while I diversify and bring in another point that I think is related to this. 'Conditions'. Hot water turns to steam, cold water freezes and in between is liquid. Human body temperature needs to be maintained between two specific points for health and maintenance of the body. Seasonal Affective Disorder reacts to light and temperature, indicating the mind is affected by physical conditions around it or can be in certain conditions. Both dwarfism and gigantism occur on islands where resources are poor or predators are weak (Galapagos Tortoises/ dwarf elephants and dinosaurs).

 

When the Earth was a boiling cauldron of lava, nothing could form here - not even crystals. When it cooled down, they could and it allowed liquid to condense too. This allowed plants to develop, in the same way that we know crystals will 'grow' (develop) in water. Until this occurred, animals couldn't develop in my opinion and did develop as roving predators because there was an evolutionary advantage to the pursuit of resources. Intelligent life would then develop as a matter of course, again in my opinion because of the need to chase resources as life developed better defenses against life (We see it driving civilization (innovation), so why not life itself?).

 

I don't see life as being that mysterious - just as the consequence of changes in the environment and these being favourable or unfavourable to its development or survival.