Miller-Urey experiment

In a footnote, Miller thanked the Nobel Prize winner Harold C. Urey for supervising his Ph.D. thesis work. Thus, this experiment became known as the Miller-Urey experiment (Sect. 4.1). Not only was the broader public impressed by these results, but also the small group of scientists who were more or less closely involved with... 

A few facts about the Miller-Urey experiments the now famous original apparatus was modified and improved by Miller himself, and by other groups, in order to improve product yields. In the reaction vessel, temperatures near the reaction zone were between 350 and 370 K, but as high as 870-920 K at the centre of the reaction. Experiments took between several hours and a whole week. The main products (starting with the highest yields) were formic acid, glycine, lactic acid and... 

Abelson (1956) carried out experiments using atmospheres containing CCb, (CO), N2, (NH3), H2 and H2O and detected small amounts of simple amino acids, the formation of which was prevented by adding oxygen. Many of the Miller-Urey experiments involved various energy sources and were carried out in the liquid and solid states as well as on gas mixtures. 

Although the Miller-Urey experiments of 1953 are of only historic interest today, they do mark the beginning of prebiotic chemistry and modern biogenesis research. 

Morowitz et al. (1995) chose a completely different route. They were able to synthesize glutamic acid from a-ketoglutarate, ammonia and formic acid in an aqueous medium without using enzymes. It is noteworthy that the reducing agent, formic acid, is one of the main products in the Miller-Urey experiment. 

Only a few years after the Miller-Urey experiment was published, J. Oro was able to synthesize one of the most important biomolecules, adenine. This purine derivative is not only a component of the nucleic acids, but as ATP, adenosine triphosphate (in combination with ribose and three phosphate residues), it plays a key role in the metabolism of all living creatures. The chemical formula of adenine is C5H5N5, or expressed in another way, (HCN)s. 

As already mentioned, hydrogen cyanide is formed in simulation experiments using reducing primeval atmospheres. CN was discovered in interstellar space as early as 1940 by optical spectroscopy (Breuer, 1974), and later HCN itself (from measurements using millimetre wavelengths). Only a few years after the Miller-Urey experiments, Kotake et al. (1956) obtained HCN in good yields by reacting methane with ammonia over aluminium-silicate contacts ... 

As early as five years after the Miller-Urey experiments, Schramm and Wissmann from the Max Planck Institute for Virus Research in Tubingen reported a successful synthesis of polypeptides using polyphosphate esters. Thus, they were able to... 

X can be any of the four nucleobases—G, A, C or U thus, four anticodons can be formed GGC, GAC, GCC and GUC. The antiparallel structure contains the codons GCC, GUC, GGC and GAC. Today, these codons code for the four amino acids alanine, glycine, valine and aspartic acid. These are, astonishingly, the four protein building blocks produced in the best yields in the Miller-Urey experiment, and they... 

Summary of laboratory experiments on chemical evolution, by the person who did the original Miller-Urey experiment. 

Fig. 4.4. This figure may be considered a window to a chemical aquarium. The core of each of the structures is carbon and most of the hemispherical structures attached to the core represent hydrogen atoms. When these molecules collide under appropriate conditions, either on the surface of a catalyst or with sufficient energy, the carbon core of two units will form covalent bonds, displacing hydrogen. The discharge chamber in the Miller-Urey experiment served to displace the hydrogen and thus to create active molecular species that would form larger covalent structures.

Figure 8.3 A photograph of (a) original set-up for the Miller-Urey experiment and (b) a reproduction of this experiment at NASA laboratories. (Partially reproduced from Lazcano and Bada [22] with kind permission from Springer Science + Business Media. Kluwer Academic Publishers 2003. Picture (b) by courtesy of NASA)...

Finding the fragments. Identify the likely source (CH4, NH3, H2O, or H2) of each atom in alanine generated in the Miller-Urey experiment. 

Duke University. Cruising Chemistry—The Miller-Urey Experiment [cited March 10, 2003]. . 

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