Life's Origin: Methane Seas & Gas Planets

[ry0225]

Howdy first post. Why is it said that life needs water to develop. Everybody says that life hear came from the sees but why could it come from a methane sea? or even beyond that on a gas planet?
Thanks Ryan

 

[hexhunter]

i'd like to know this aswell, please awnser

 

[Monique]

Water is a great solvent with a high di-electric constant.

 

[ry0225]

Water is a great solvent with a high di-electric constant.

Why would that eliminate all others?

 

[gerben]

It would be important that the medium would allow many different chemical reactions to occur, as life is somehow a complicated chemical balance.

 

[DaveC426913]

Water is an incredible substance.
- It is one of the few chemicals that have a broad temp. range of liquid state. This allows for excellent chemical interaction.
- It is an almost universal solvent. It can dissolve most things, including rocks containing minerals that life needs.
- It is one of the lightest molecules in existence. (atomic weight of 10).
- it has a very high heat capacity, meaing it absorbs and holds heat extremely well.
- Its solid state is more buoyant than its liquid state - large bodies will freeze from the surface down, unlike all other liquids, which will freeze from the bottom up. Large bodies of water are protected from freezing, allowing life to exist and fluorish though winters.

The list goes on and on. Some day, I'll compile a list of things that make water an excellent choice for life, beating out all others.

(Another list shows why carbon is an equally excellent choice for the basis of life. It is unique in the periodic table.)

 

[hexhunter]

while we're on it, why is Oxygen so wonderful, this might be a chemistry question, but why is it so important to combustion, and equally, why is it so important to life?

 

[DaveC426913]

A factor to consider when examining chemical constituents of molecules is that all elements are not created equal (I mean in terms of usefullness). The universe is strongly biased towards those elements nearest the beginning of the table, where elements are light, strongly interactive, flexiable and abundant. As we get into heavier and heavietr elements, the combinations are less varied and less interesting.

Thus:
Hydrogen: really light, really useful,
Helium: inert,
Lithium, Boron, Beryllium: (I dunno, good question),
then the really intreresting ones: Carbon, Nitrogen, Oxygen,
As you go up the table, the roles filled by heavier elements can more efficently be filled by lighter ones, where you get more bang for your buck.

Re: Oxygen. With the exception of fluorine (and inert helium), Oxygen is the lightest, and rightmost element on the table. It combines with Hydrogen, the lightest and leftmost element on the table, and the most abundant element in the universe. These two opposites combine with the greatest release of energy, which means they provide the biggest bang for the buck. (and which is why they're what is used in rockets).

So, this begs the question:
Obviously my logic is shaky. Why do lithium, boron and beryllium, as well as fluorine play relatively small roles in chemistry (compared to H, C, N, O)?

 

[watermint]

I know oxygen can help people live. People breathe in oxygen.

 

[watermint]

I think all chemical elements play equal inportant roles in the Universe, only when people need some of them, then those become more important than others.

 

[DaveC426913]

Well...

oxygen and hydrogen were powering life on Earth long before humans came along to decide what was or wasn't important.

Hydrogen and helium were powering every star in the universe long before Earth was even a dustball.

I feel comfortable saying that hydrogen plays a more important role in the universe than, say, yttrium.

 

[Bladibla]

I would think it because water is the reagent which hydrolyses majority of organic substances into smaller amino acids/carbohydrates/whatever, and also in the opposite case, where condensation (in most cases produce H2O) allows peptide bonds/Phosphodiester bonds/glycosidic bonds/ester bonds to form.

Self-relicating molecules are the key to life, and since H2O plays 'I break you up or join you together!' part, it would be pretty important.

 

[Hurkyl]

IIRC, oxygen isn't important to life in general -- just life adapted to breathing oxygen. We didn't really have much oxygen in the atmosphere until some organisms started producing it to poison off the competition...

(I suppose there might be an argument it's important for more complex lifeforms, though, but I can't make that one!)

 

[Phobos]

Why would that eliminate all others?

It doesn't eliminate other possibilities. It's just much more likely, given what we know about life & biochemistry.

 

[Phobos]

while we're on it, why is Oxygen so wonderful, this might be a chemistry question, but why is it so important to combustion, and equally, why is it so important to life?

oxygen is one of the most efficient "electron acceptors"

...if I had the time, I'd dig up a comparison to other types of electron acceptors which can be used

 

[Monique]

The problem with oxygen is that it forms free radicals, very toxic to life. Oxygen is a very good electron acceptor, as Phobos said, but the release of energy from oxygen is very explosive; the energy that can be extracted from it would be very inefficient without the electron transport chain in the mitochondria, which tap the energy step by step.

 

[Minorail]

Hello, momique, I think only under some specil condition will oxigen form radicals, or all of us should not live same this. conluson oxygen dangeros to life is not true. u think so too, i know that.

 

[Monique]

Not true, we have a whole system of anti-oxidants in our system. An example I can give you is superoxide dismutase, an enzyme that catalyzes the dismutase reaction of toxic superoxide radicals to molecular oxygen and hydrogen peroxide. Oxidative stress is one of the reasons why we get old, people living at great hights are said to live longer, due to the lower oxygen tension.

 

[Monique]

I think only under some specil condition will oxigen form radicals, or all of us should not live same this.

The special condition is in the mitochondria, along the respiratory electron transport chain. Electrons formed during the oxidation of glucose are passed along the electron transport chain to electron accepting molecules embedded in the mitochondrial membrane. These molecules then produce free protons, which ultimately drive ATP synthesis.

In the final step of electron transfer, electrons combine with oxygen and protons to produce water. It is possible that by mistake the electron is accepted by molecular oxygen (O2), leading to the formation of superoxide free radicals (O2.-). It is said that this electron leak converts about 1-3% of oxygen molecules into superoxide.

AND you must know that neutrophil cells of the immune system use respiratory burst to generate a large quantity of free radicals. These are packed in granules and released to the outside of the cell to kill bacteria.

 

[Minorail]

[quote-monique]AND you must know that neutrophil cells of the immune system use respiratory burst to generate a large quantity of free radicals. These are packed in granules and released to the outside of the cell to kill bacteria.[/quote]
What you nmean ? do you think you are trying toi be correctly stating it or just kind of metaphor explaning how atigen antibody tcell.in action ?

by the way, i think saying ATP synthesis is driven by proton sound really strange, this stuff must be in enzyme instead.

 

[Minorail]

It is possible that by mistake the electron is accepted by molecular oxygen (O2), leading to the formation of superoxide free radicals (O2.-). It is said that this electron leak converts about 1-3% of oxygen molecules into superoxide.

again never such posibility. u heard of any case which patien poinsoned by what you said. i think such way of explaining is not correct. and misleding people to wrong assumption.
such chemica reaction true it can happen in nature, universe around us, radical soon destroyed in air or in human body by other oxygen atom or molecula

 

[Monique]

What you nmean ? do you think you are trying toi be correctly stating it or just kind of metaphor explaning how atigen antibody tcell.in action ?

I'm not sure what you just said here.

by the way, i think saying ATP synthesis is driven by proton sound really strange, this stuff must be in enzyme instead.

It is a proton gradient that drives ATP synthesis. Due to the gradient that is set up by the electron transfer, protons start moving from one side of the membrane to the other. They move through channels of ATP synthase, a very clever molecule. You can see the process happening in this animation http://www.sp.uconn.edu/~terry/images/anim/ATPmito.html you can see the electron transport here http://www.sp.uconn.edu/~terry/images/anim/ETS.html

 

[Monique]

again never such posibility. u heard of any case which patien poinsoned by what you said. i think such way of explaining is not correct. and misleding people to wrong assumption.
such chemica reaction true it can happen in nature, universe around us, radical soon destroyed in air or in human body by other oxygen atom or molecula

That is the problem: the radicals are very reactive and will attack the proteins that are next to it, the fact that we have enzymes such as SOD (superoxide dismutase) shows that the free radicals need to be neutralized before they react with something else.

 

[DaveC426913]

The problem with oxygen is that it forms free radicals, very toxic to life. Oxygen is a very good electron acceptor, as Phobos said, but the release of energy from oxygen is very explosive; the energy that can be extracted from it would be very inefficient without the electron transport chain in the mitochondria, which tap the energy step by step.

Saying oxygen is harmful to life (not that I'm claiming you said that...) is like saying gasoline is harmful to cars. Any fuel source is, by definition, capable of releasing its energy in unproductive and harmful ways. Even when released in productive ways there are still undesirable side effects. You still want the oxygen/gasoline, because otherwise you're just a doorstop. It's just not a perfect energy source.

 

[Monique]

Well, I said that free radicals are bad, oxygen has the specific physical conditions that allows it to take up an unpaired electron.

 

[DaveC426913]

Yah, I was attempting to head off the more general argument that seems to be appearing in this thread, that oxygen is somehow not good for living things.

 

[Mental Gridlock]

Oxygen is poison to certain bacteria, like Methanogens, which comprised part of the original makeup of life on Earth. Oxygen is much more essential to modern life today than it applied to early life on Earth, when the planet had less oxygen. I'm not trying to say oxygen isn't important to all life on Earth, just certain life on Earth.. And so I'm wondering: Can life exist on a planet with no H20 Whatsoever??

 

[matthyaouw]

Can life exist on a planet with no H20 Whatsoever??

Life as we know it- no. Water is essencial for dissolving various nutrients, acting as a transport medium, etc. Cells are composed mostly of water.

 

[nipwoni]

Originally, oxygen was poisonous to all life. Then bacteria started splitting water in photosynthesis and producing oxygen, and oxygen built up in the atmosphere. At the time oxygen was still poisonous to the bacteria that were producing it. Eventually aerobic bacteria evolved that could use oxygen, and they were able to deal with the damaging effects of oxygen. Oxygen still is damaging to all life, but most organisms can now neutralize it and repair the damage. It's not just damaging because it's a fuel.

 

[Huckleberry]

Would water also be vital to life because of its PH balance? H2O could also be written HOH. H forms acids and OH forms bases. When acids and bases combine in a solution they make water.

Another interesting thing about water is that it does not compress like most liquids. It changes very little in volume even when great pressure is applied to it. This is why a wave can travel across an ocean and not lose much amplitude.

Water vapor is also a greenhouse gas. It helps absorb energy from the sun and distribute it across the Earth. One side of the planet does not burn while the other freezes solid.