quarta-feira, 30 de abril de 2014

Nova Teoria Sobre A Origem da Vida: Sob Analise.

Non‐enzymatic glycolysis and pentose phosphate pathway‐like reactions in a plausible Archean ocean

http://msb.embopress.org/content/10/4/725

Resumo feito por um ateu na briga contra criacionistas:

 
More evidence of protobiotic life:

https://www.youtube.com/watch?v=gHbYJfwFgOU

Ralser's team took early ocean solutions and added substances known to be starting points for modern metabolic pathways, before heating the samples to between 50 ˚C and 70 ˚C – the sort of temperatures you might have found near a hydrothermal vent – for 5 hours. Ralser then analysed the solutions to see what molecules were present.
"In the beginning we had hoped to find one reaction or two maybe, but the results were amazing," says Ralser. "We could reconstruct two metabolic pathways almost entirely."
The pathways they detected were glycolysis and the pentose phosphate pathway, "reactions that form the core metabolic backbone of every living cell," Ralser adds. Together these pathways produce some of the most important materials in modern cells, including ATP – the molecule cells use to drive their machinery, the sugars that form DNA and RNA, and the molecules needed to make fats and proteins.
If these metabolic pathways were occurring in the early oceans, then the first cells could have enveloped them as they developed membranes.
In all, 29 metabolism-like chemical reactions were spotted, seemingly catalysed by iron and other metals that would have been found in early ocean sediments. The metabolic pathways aren't identical to modern ones; some of the chemicals made by intermediate steps weren't detected. However, "if you compare them side by side it is the same structure and many of the same molecules are formed," Ralser says. These pathways could have been refined and improved once enzymes evolved within cells.
http://www.newscientist.com/article/dn25471-spark-of-life-metabolism-appears-in-lab-without-cells.html#.U2mZL8fHKh0

Basically, they mixed the oldest of ocean chemistries and 5 hours of heat and arrived at 29 different metabolic pathways, including the precursor of ATP/RNA/DNA.... Now, that was in 5 hours. Imagine a week, or a month or a few million years!!! And no, it isn't complete abiogenesis, but it is another nail in the coffin of mythological 'creation'....


PESQUISA:

The reaction sequences of central metabolism, glycolysis and the pentose phosphate pathway provide essential precursors for nucleic acids, amino acids and lipids.

Metabolismo (do grego metabolismos, μεταβολισμός, que significa "mudança", troca1 ) é o conjunto de transformações que as substâncias químicas sofrem no interior dosorganismos vivos. O termo "metabolismo celular" é usado em referência ao conjunto de todas as reacções químicas que ocorrem nas células. Estas reacções são responsáveis pelos processos de síntese e degradação dos nutrientes na célula e constituem a base da vida, permitindo o crescimento e reprodução das células, mantendo as suas estruturas e adequando respostas aos seus ambientes. ( cont.) 

Glicólise (do grego antigo "γλυκύς" (glykýs), adocicado e "λύσις" (lýsis), quebra, degradação) é a sequência metabólica composta por um conjunto de dez reações catalizadas por enzimas livres no citosol, na qual a glicose é oxidada produzindo duas moléculas de piruvato, duas moléculas de ATP e dois equivalentes reduzidos de NADH+, que serão introduzidos na cadeia respiratória ou na fermentação.1 A glicólise é uma das principais rotas para geração de ATP nas células e está presente em todos os tipos de tecidos.


A via das pentoses-fosfato, ou mais simplesmente via das pentoses, é uma via alternativa de oxidação de glicose-6-fosfato, que leva à produção de 3 compostos, a ribose-5-fosfatoCO2 e o NADPH.

 However, their evolutionary origins are not yet understood. Here, we provide evidence that their structure could have been fundamentally shaped by the general chemical environments in earth's earliest oceans. We reconstructed potential scenarios for oceans of the prebiotic Archean

Na escala de tempo geológico, o Arqueano ou Arcaiqueano (antes Arqueozoico) é o éon que está compreendido aproximadamente entre 3,85 bilhões de anos e 2,5 bilhões de anos atrás. O éon Arqueano sucede o éon Hadeano e precede o éon Proterozoico. O início do Arqueano é marcado pelas primeiras formas de vida unicelulares da Terra.


Nenhum comentário:

Postar um comentário