ATP and pre-life

[pioneer]

Although RNA replicators may have defined the inception of basic life, a question to comes to mind is connected to ATP. In modern times, there are thousands of proteins that use ATP. If the earliest proteins formed first, say from the dehydration of animo acids in clays, is it possible that the concentration of ATP and other nucleoside triphosphates would remain too low to support active replicators?

 

ATP is an electron acceptor. All that would be needed to bleed its energy potential is a suitable electron releasing group such as -OH. Since this group is built into so many different proteins, isn't it likely that even a random protein distribution, would quickly react with ATP, depriving the RNA replicators? What this suggests is that proteins needed to evolve beyond being a nuisance until they could help regenerate or even increase the concentration of ATP and other nucleoside triphosphates. Then the RNA replicators had a shot at evolving.

Edited December 14, 2010 by pioneer

[Edtharan]

Based on the work by Dr. Jack Szostak, it is possible that the first replicators were not self replicators and requiered processes outside of them to allow them to replicate. In the case that Dr. Jack Szostak proposes, it is a convection curent set up by undersea thermal vents.

 

When neucleotide base paied strands get hot, they seperate into two complimentary strands, then when they cool down again, they can reform with single neucleotides pairing up and polymerising into a new strand (and since there were two strands to start with, we now have four strands - replication). This process is the core of the polymerase chain reaction (PCR) used by biologists studding DNA.

 

As neucliotide chanins can have secondary enzymatic activity (such as with RNA), then with high energy molecules (ATP like molecules) this could produce chemicals that could be used to create new neucliotide monomers, thus increaseing the rate that the neucleotide sequence could be replicated (it would no longer need neucleotide monomers to difuse through the vesicle wall, but be produced from inside the vesicle).

 

Any secondary structures, and chemicals produced from enzymatic activity of the neucleotide strands that created these high energy molecules would help speed up the replication process, and allow it to occur away from the heat source. This would give 3 main advantages:

 

1) It would allow the vesicle to replicate away form the energy source.

2) Increased replication rates as the vesicle would not need to be near the heat source to replicate.

3) These high energy molecules would allow other chemical processes to occur increaseing the potential chemical toolbox of the vesicle

 

At this point, the vesicle has achieved self replication and could be considdered an organism.