Theoretical origin of life; another theory: (Introduction)

by David Turell @, Tuesday, June 02, 2015, 15:57 (3462 days ago) @ David Turell

this one involves the polarity of amino acids without explaining where they came from or that you can't polymerize in hot water. Great just-so story:-http://www.sciencedaily.com/releases/2015/06/150601172834.htm-"In the beginning, there were simple chemicals. And they produced amino acids that eventually became the proteins necessary to create single cells. And the single cells became plants and animals. Recent research is revealing how the primordial soup created the amino acid building blocks, and there is widespread scientific consensus on the evolution from the first cell into plants and animals. But it's still a mystery how the building blocks were first assembled into the proteins that formed the machinery of all cells.-
"Now, two long-time University of North Carolina scientists -- Richard Wolfenden, PhD, and Charles Carter, PhD -- have shed new light on the transition from building blocks into life some 4 billion years ago.-"'Our work shows that the close linkage between the physical properties of amino acids, the genetic code, and protein folding was likely essential from the beginning, long before large, sophisticated molecules arrived on the scene," said Carter, professor of biochemistry and biophysics at the UNC School of Medicine. "This close interaction was likely the key factor in the evolution from building blocks to organisms."-"Their findings, published in companion papers in the Proceedings of the National Academy of Sciences, fly in the face of the problematic "RNA world" theory, which posits that RNA -- the molecule that today plays roles in coding, regulating, and expressing genes -- elevated itself from the primordial soup of amino acids and cosmic chemicals to give rise first to short proteins called peptides and then to single-celled organisms.-Wolfenden and Carter argue that RNA did not work alone; in fact, it was no more likely that RNA catalyzed peptide formation than it was for peptides to catalyze RNA formation.-***-"Proteins must fold in specific ways to function properly. The first PNAS paper, led by Wolfenden, shows that both the polarities of the twenty amino acids (how they distribute between water and oil) and their sizes help explain the complex process of protein folding -- when a chain of connected amino acids arranges itself to form a particular 3-dimensional structure that has a specific biological function.-My comment:Specific biologic function is exactly what is wanted, but life is a mass of those functions cooperating together. Seems the authors lightly skip by that point. Smells of planning to me.-"'Our experiments show how the polarities of amino acids change consistently across a wide range of temperatures in ways that would not disrupt the basic relationships between genetic coding and protein folding," said Wolfenden, Alumni Distinguished Professor of Biochemistry and Biophysics. This was important to establish because when life was first forming on Earth, temperatures were hot, probably much hotter than they are now or when the first plants and animals were established.-"A series of biochemical experiments with amino acids conducted in Wolfenden's lab showed that two properties -- the sizes as well as the polarities of amino acids -- were necessary and sufficient to explain how the amino acids behaved in folded proteins and that these relationships also held at the higher temperatures of Earth 4 billion years ago.-"The second PNAS paper, led by Carter, delves into how enzymes called aminoacyl-tRNA synthetases recognized transfer ribonucleic acid, or tRNA. Those enzymes translate the genetic code."


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