Self replication

The FIS reaction (section A3.14.3.2) has been studied in a CFUR and revealed a series of stmctiires known as serpentine patterns also, the birth, self-replication and death of spots , corresponding to regions of high concentration of particular species (see figure A3.14.17 have been observed [46]. 

Figure A3.14.17. Self-replicating spots in the FIS reaction in a CFUR, comparing an experimental time sequence with numerical simulation based on a simple autocatalytic scheme. (Reprmted with pennission from Lee etal [M], Macmillan Magazines Ltd. 1994.)...

A particularly interesting type of micellar catalysis is the autocatalytic self-replication of micelles [58]. Various examples have been described, but a particularly interesting case is the biphasic self-reproduction of aqueous caprylate micelles [59]. In this system ethyl caprylate undergoes hydroxyl catalysed hydrolysis to produce the free carboxylate anion, caprylate. Caprylate micelles then fonn. As these micelles fonn, they solubilize ethylcaprylate and catalyse further production of caprylate anion and caprylate micelles. 

Kemp s Acid Enzyme-Cleft and Self-Replication Models... 

Kemp s Acid Enzyme-Cleft and Self-Replication Models 347 5.2.1 Enzyme-Cleft Models with Convergent Functional Croups... 

There was a sense however that the sequence that later came to be called RNA World was the most reasonable one RNA World denotes an early period in the development of self replicating systems... 

Even if It could be shown that RNA preceded both DNA and proteins in the march toward living things that doesn t automatically make RNA the first self replicating molecule Another possibility is that a self replicating polynucleotide based on some carbo hydrate other than o ribose was a precursor to RNA Over many generations natural selection could have led to the replacement of the other carbohydrate by D ribose giving RNA Recent research on unnatural polynucleotides by Professor Albert Eschenmoser of the Swiss Federal Institute of Technology (Zurich) has shown for example that nucleic acids based on L threose possess many of the properties of RNA and DNA... 

The following sections contain a review of many of the varied synthetic systems that have been developed to date utilising noncovalent interactions to form assembhes of molecules. These sections are loosely demarcated according to the most important type of noncovalent interactions utilized in conferring supramolecular order (ie, van der Waal s interactions, electrostatic interactions, and hydrogen bonds). For extensive reviews, see References 1,2,4—6,22,46,49,110—112. Finally, the development of self-assembling, self-replicating synthetic systems is noted. 

Analytical chemistry having an interdisciplinary character cannot set aside the attractive power and advances of supramolecular chemistry - the chemistry beyond the molecule or the chemistry of molecular assemblies and of intermolecular bonds as defined by Jean-Marie Lehn, who won the Nobel Prize in 1987. Recognition, reactivity, and transport, as well as self-assembly, self-organization and self-replication are the basic functional features of supramolecular species and chemistry. 

It should be mentioned that in the last few years super-cooled water has attracted the interest of many scientists because of its exceeding properties and life at temperatures below 0 °C 1819). Speedy recently published a model which allows for the interpretation of the thermodynamic anomalies of supercooled water 20). According to this model there are hydrogen bonded pentagonal rings of water molecules which have the quality of self-replication and association with cavities. 

J. vonNeumann, in Theory of Self-Replicating Automata, A. Burks, ed. University of Illinois... 

R. A. Freitas Jr. and R. C. Merkle, Kinematic Self-Replicating Machines, Landes Bioscience, Georgetown, TX, 2004. 

All biological organisms have the ability to reproduce themselves. The instructions for self-replication are stored and transmitted by macromolecules called nucleic acids. There are two types of nucleic acids, one that stores genetic information and one that transmits the information. Genetic information is stored in molecules of deoxyribonucleic... 

Winter, A. E. (1996), Autocatalysis and the generation of self-replicating systems , Acta Chem. Scand., 50, 469-485... 

Life is a population of RNA molecules (a quasispecies) which is able to self-replicate and to evolve in the process. ... 

The search for life in the cosmos requires a generalised, universal definition of life. This must take into account the properties of systems ranging from viruses, prions, denucleated cells or endospores to life in a test tube, computer viruses or even to robots which are capable of self-replication. 

In addition, the authors suggest that all such systems must have a semi-permeable active boundary (membrane), an energy transduction apparatus and (at least) two types of functionally interdependent macromolecular components (catalysts and records). Thus, the phenomenon of life requires not only individual self-replication and self-sustaining systems, but it also requires of such individual systems the ability to develop a characteristic, evolutionary dynamic and a historical collectivist organisation. 

New developments in chemistry can arise from the planning and testing of new synthetic methods. In contemporary chemistry, we can see developments whose roots can be found in biological processes, as the terms signal recognition , replication , autocatalysis or self-replication indicate. Modern ideas in these areas can be found in laboratories where work on peptide chemistry is being carried out. 

The scientific world was amazed to hear that David Lee, from the laboratory of Reza Ghadiri (Scripps Research Institute, La Jolla, California), had found a self-replicating peptide (Lee et al., 1996) there are analogies to the experiments with oligonucleotides (see Sect. 6.4). Lee was able to show that a certain peptide, containing 32 amino acids, can both function as a matrix and also support its own synthesis autocatalytically. The information transfer is clearly more complex than that involved in nucleic acid replication. In the case of this particular peptide, both the... 

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