How Complex Chemical Reactions Emerged On Earth? A Scenario

[Moontanman]

The molecular and phase bandwidth between water and oil, is higher than between ammonia and an unknown X, since ammonia is in the middle between water and oil. If you started with ammonia, your molecular and phase bandwidth becomes narrower, making life less likely than in water, which has a wider phase bandwidth. 

 

If you look in terms of energetics, which is critical to life, since you can burn ammonia in oxygen to make water and NOx, water also has an extra energy band width. Even if life did evolve in ammonia, any organic solvent or even hydrogen, life will evolve to use these solvents for food and burn them to water. Once it reaches water, it can't go lower and will have to stop there. 

 

An increase in entropy needs energy. The higher energy bandwidth of water, relative to organics, means water maximizes the energy output for entropy/change by being the lowest floor. All else equal, water will reach the finish line first; based on energy output, and will eat its slower competitors for energy. 

 

 

Again you make assumptions about oxygen metabolism and temperature based on Earth life. We do not know if life has to be exactly like life on earth or even if it has to be the same chemicals. If i had to guess i would have to guess Earth like life as well but it would at this point be speculation, nothing more. 

 

I think water would be favored over ammonia for similar reasons as well but again that is extrapolating from life as we know it made up of the chemicals we know. At this point it may very well be that Earth life is the oddity and most life is based in chemicals we wouldn't even dream of. Unlikely you say? Possibly but again drawing a line from one data point is impossible. We should keep our options and eyes open. 

 

The most we can say about earth life is that it is based in water and on carbon and that energy gradients, particularly chemical and temperature but possibly also physical have had much to do with life developing here. 

 

Surface life we see and are a part of, complex life, is the real extremophile, most earth life is uses chemicals other than oxygen for energy and chemosynthesis instead of photosynthesis.

 

Lets not put the car before the horse, yes conditions on earth are favorable for earth like life but think of how astonishing it would be if that were not true.  

 

Just as astonishing if we found life on Titan and it wasn't optimized to the conditions on Titan. 

[HydrogenBond]

Life on other planets has a much proof as big foot and unicorns. The reality is the ancient assumption tat only the earth has life have never been disproven in hundreds of years. I am not saying this is settled science , but science is about what the data says, and not about what we wish to be true.

[Moontanman]

Life on other planets has a much proof as big foot and unicorns. The reality is the ancient assumption tat only the earth has life have never been disproven in hundreds of years. I am not saying this is settled science , but science is about what the data says, and not about what we wish to be true.

 

 

HB, you are correct but to simply assume these things are what they are and cannot be anything else negates what we know about chemistry not to mention evolution. I agree that from what we see water/carbon/ protean/nucleic acids is the perfect system but my contention is that we cannot say so with any degree of authority anymore than we can say absolutely there is no bigfoot or aliens, we simply cannot be sure, all we can do is say we have one data point and need more before we can plot a curve... We have no idea where we sit on the curve or even if there is a curve. Making absolute claims is not supported.... 

 

I'd rather keep my options open...

[HydrogenBond]

By knowing about the water system and how its works, one can set up parallels with other solvents and infer what it might need to happen for it to work. Proteins fold due to hydrophobic interactions. This is driven by a need to get away from water.  If we used organic solvents for the same protein, these will shield the normal hydrophobic actions needed for folding because these groups will bind with the organic solvent.

 

To use an alternate solvent, one will need a different type of protein analogous material that will have groups that are  phobic to that  solvent, while also being very pliable in terms of variety and polymerization. 

[Moontanman]

By knowing about the water system and how its works, one can set up parallels with other solvents and infer what it might need to happen for it to work. Proteins fold due to hydrophobic interactions. This is driven by a need to get away from water.  If we used organic solvents for the same protein, these will shield the normal hydrophobic actions needed for folding because these groups will bind with the organic solvent.

 

To use an alternate solvent, one will need a different type of protein analogous material that will have groups that are  phobic to that  solvent, while also being very pliable in terms of variety and polymerization.

You do realize this has been at least partly worked out for liquid methane?

[HydrogenBond]

You do realize this has been at least partly worked out for liquid methane?

 

 

One problem is the cold temperature of liquid methane, is not conducive to reaction kinetics. However, as an intellectual exercise, you could have hydrophilic driven protein folding in methane. The problem will be the cold. Place a steak in a -160 C freezer and see if you can fold it. DNA freezes at -2C. Maybe they should use hexane. 

[Moontanman]

One problem is the cold temperature of liquid methane, is not conducive to reaction kinetics. However, as an intellectual exercise, you could have hydrophilic driven protein folding in methane. The problem will be the cold. Place a steak in a -160 C freezer and see if you can fold it. DNA freezes at -2C. Maybe they should use hexane.

The problem is solved by using chemicals that are less stable than the ones we use...

[HydrogenBond]

The Miller experiments of the 1950's, which have been repeated with other starting materials, resulted in amino acids and other molecules needed for life. These experiments used electric sparks to simulate large thunderstorms on the earth's primitive surface. 

 

 

Originally it was thought that the primitive secondary atmosphere contained mostly ammonia and methane. However, it is likely that most of the atmospheric carbon was CO₂ with perhaps some CO and the nitrogen mostly N₂. In practice gas mixtures containing CO, CO₂, N₂, etc. give much the same products as those containing CH₄ and NH₃ so long as there is no O₂. The hydrogen atoms come mostly from water vapor. In fact, in order to generate aromatic amino acids under primitive earth conditions it is necessary to use less hydrogen-rich gaseous mixtures. Most of the natural amino acids, hydroxyacids, purines, pyrimidines, and sugars have been made in variants of the Miller experiment.^[9][25]

 

The impact of water is to first make large thunderstorm that generate lightning. The lightning sparks simple atmospheric chemicals, in the presence of cloud's water, stripping off hydrogen atoms from water, which then combine to form a wide variety of precursor chemicals. 

 

The gas and water mixture is made unstable, being pushed up an energy hill by the lightning spark. The constant energy of the spark then cause the materials to rearrange into i higher energy but stable states; amino acids emerge at P. The natural stability of amino acids, make them useful. They all have the stink of water, because water is planning ahead. 

 

 

Edited August 20, 2015 by HydrogenBond

[minus]

Have the entropic changes of a living system actually being directly measured in some way? I mean, how do we even know that life creation and maintenance is associated  with entropic decreases? What is the evidence based facts behind these assumptions? 

[HydrogenBond]

Say we took a photo snap shot of a small tree sapling, each day, until it becomes a mature tree. And say we could trace all the atoms from which its structures are composed, from their beginnings in water, air and land. What you would see is the entropy of these atoms lowering as the tree grows and these atoms become integrated into elaborate polymer structures. I call this particular layer structural or configurational entropy where simple materials are assembled into elaborate polymers with precise order, relative to the simple starting materials.The entropy in each snap show entropy lowering into ordered structures. 

 

After the tree reaches maturity, we chop it down to end its life. Now it is an animate object; firewood. If we burn it, it will give off energy and the entropy of its atoms will increase again as the fire makes simple materials like CO2 and H2O and various soluble minerals. The CO2 is a gas with many degrees of freedom. 

 

There is another layer to life. Cells depolymerize and metabolize food materials and therefore turn larger complex things into simple things, like CO2 and water. This action causes entropy to increase. This is what I will call metabolic entropy, which always increases. The sum of metabolic (+) and structural (-) entropy is always positive, even for life; there is a net entropy increase. But life is different from inanimate matter, in that it has this layer of negative entropy that lingers at each stage of growth connected to its structures. This is easier to isolate with snap shots, because with time stopped by the snap shot, metabolic entropy is zeroed out. 

 

Since the entropy of the universe has to net increase, it makes sense that metabolic entropy was the first to appear since what it does is not much different from inanimate matter and fire. It does not need growth and life, since the structural entropy layer can be simple. RNA replicators become much more connected to structural entropy lowering, and this would come later.

 

In other words, the better the metabolic entropy increase, the more potential there is for growth and negative entropy, while still allowing net positive entropy.  

 

An interesting observation are proteins fold with exact folds. Before biology could investigate this, it was assumed protein had average folds due to thermal vibrations. It was assumed a moderate amount of entropy in protein folding, which would be consistent with a random model of life. But later it was found out this expected entropy did not exist. Folding was not random but appears to be connected to the structural entropy layer; gets negative enough to cancel out random. 

Edited September 2, 2015 by HydrogenBond

[minus]

Question: If we let alone a cell in an isolated box, the result will eventually be a chemical mixture and not the organized cell. The final disordered mixture is more entropic than the the organized cell. Doesn’t this prove that lowering entropy is a hallmark of life and every organism spends an amount of energy to increase its order??

 

Answer: Not necessarily. The story of any individual living being actually is a journey towards gradual decay into disordered chemistry. In the beginning it’s a zygote in which so much information is disclosed about future events, patterns, etc in a very small space. So we can say that a zygote has less entropy compared to later stages. This entropy gradually increases as we become infants, childs, teenagers, adults, etc, because less and less information is carried over time…

A simple cell in isolation will indeed decay quickly, but don’t forget that cells never exist in isolation, and higher organisms are much more complex and they interact with external energy. So the fact that they don’t instantly decay doesn’t necessarily mean that they use energy to decrease their entropy. Never underestimate our inability to fully comprehend the value of huge numbers.

 I will explain:

Lets assume that a human body everyday degrades towards a higher entropic state. Lets assume for this reason, that after each day, the body loses, lets say 100 thousand of chemical reactions. Suppose we have an 80 years old man. He has lived 29200 days. This means that he has lost nearly 3 billion reactions during his lifetime. If the total amount of chemical reactions he has is, lets say 1 trillion, then after 80 years he will be composed of 997 billion reactions, which means virtually still 1 trillion. So the impact of the whole process on the chemical reaction count will be almost negligible.

Of course, if we stop giving him food, he will degrade faster, but this is an example how can life can be compatible with a gradual loss of entropy.

 

 

 

 

Question: Isn’t a cell is much more ordered than its components?

 

Answer: A cell is much more ordered than its components, but what you forget is that a cell never exists in isolation. It owes its existence and its properties to the fact that it belongs into a more generalized phenomenon that is called life, which is an open system and interacts with external energy.

Imagine you have a flask with water that is heated with fire. The molecules of water will start speeding randomly toward various directions. Virtually, what you are doing here with the cell argument is ignoring the fire and the majority of other water molecules and focusing only on subset of 2 specific molecules. These molecules will be perceived as gaining speed without an obvious reason, thus seeming to decrease entropy, as well as other known laws is such a way that it has to be characterized as an independent phenomenon that has to be studied….

 

 

 

Question: Isn’t glucose and oxygen more ordered than CO2 and water?

Answer: In order to build a house, you take the bricks and put them together. But you don’t build a cell in that way. A cell or a living being is the way it is because of the other living beings, ie because of the existence of what we call life on earth. Cells or living beings never exist in isolation.

 

Question: Isn’t it difficult to measure changes in order in particular organisms or cells?

Answer: Yes, but if life as a whole is a sum of entropy decreasing entities, then the entropy of the whole system will be decreasing accordingly over time. In this case, the total amount of entropic releases in the environment will be changing over time accordingly. I think this can be measurable....

[minus]

And now that we found water on Mars, it is a first class chance to test all those water-based theories with respect to the origin of life!

 

We are all waiting to see! We truly live in amazing times....

 

 

A possible setback is that they have found that crater Gale is the bottom of an ancient watery lake that existed for a significant amount of time in the past. This is evidence that the climate of Mars used to be warmer and the atmosphere thicker. However, does the absence of fossils or any organic remnants of ancient microbial life suggests that life probably never existed there despite the presence of water?

 

[Moontanman]

And now that we found water on Mars, it is a first class chance to test all those water-based theories with respect to the origin of life!

 

We are all waiting to see! We truly live in amazing times....

 

 

A possible setback is that they have found that crater Gale is the bottom of an ancient watery lake that existed for a significant amount of time in the past. This is evidence that the climate of Mars used to be warmer and the atmosphere thicker. However, does the absence of fossils or any organic remnants of ancient microbial life suggests that life probably never existed there despite the presence of water?

 

 

Some new thoughts on the possibility of non water based life is being discussed, interestingly even the possible size of cells in liquid methane has been asserted, we might not need a microscope to see single celled microbes on Titan, a yard stick might be more appropriate.. 

 

https://www.youtube.com/watch?v=kG2-GqJnCXY

[minus]

Wow!! That was an amazing documentary! Watched it all..Thanks for the link.

Although definitely some places in Titan are lifeless, and obviously there is no intelligent life there (thats what we know for sure), the finding of hydrogen depletion in its lower atmosphere is very interesting! I am so thirsty to find out what is happening.

 

Despite that our curiosity needs to be fed with answers here and now, we have to wait many years for further missions to do so.  Unfortunately, space exploration is time consuming.

 

P.S. So many times, even our most basic predictions about conditions on planets were proved to be wrong when robots were send to confirm our hypotheses, which underscores how difficult it is to make predictions...It also shows that most of the things we think we know about the Universe are false 

 

 

[minus]

NASA has recently revealed astonishingly breath taking images of the surface of Pluto. However, it is evident that there is no complex chemistry on its surface. At least not much of it. That means that future missions will focus (like in the case of Mars) on spending time and money for the search of a needle in a haystak!! However, its worth the try...

 

https://www.nasa.gov/feature/new-horizons-returns-first-of-the-best-images-of-pluto