Genetic code discovery

The sequencing of the human genome has been widely touted as a critical scientific milestone that will revolutionize the process of drug discovery. The continuing analysis of the human genetic code will provide the scientific framework on which... 

This revolution in our understanding of the structure of DNA inevitably stimulated questions about its function. The double-helical structure itself clearly suggested how DNA might be copied so that the information it contains can be transmitted from one generation to the next. Clarification of how the information in DNA is converted into functional proteins came with the discovery of both messenger RNA and transfer RNA and with the deciphering of the genetic code. 

Consolidation of the results from many experiments permitted the assignment of 61 of the 64 possible codons. The other three were identified as termination codons, in part because they disrupted amino acid coding patterns when they occurred in a synthetic RNA polymer (Fig. 27-6). Meanings for all the triplet codons (tabulated in Fig. 27-7) were established by 1966 and have been verified in many different ways. The cracking of the genetic code is regarded as one of the most important scientific discoveries of the twentieth century. 

Following Zamecnik s discovery that ribosomes are the complexes responsible for protein synthesis, and following elucidation of the genetic code, the study of ribosomes accelerated. In the late 1960s Masayasu Nomura and colleagues demonstrated that both ribosomal subunits can be broken down into their RNA and protein components, then reconstituted in vitro. Under appropriate experimental conditions, the RNA and protein spontaneously reassemble to form 30S or SOS subunits nearly identical in structure and activity to native subunits. This breakthrough fueled decades of research into... 

Following the discovery of DNA structure and the genetic code, various associated techniques involving the manipulation and separation of DNA fragments have been developed. Several of the physical methods are useful in nucleic-acid biochemistry these include, centrifugation, electrophoresis and chromatographic separation of DNA fragments. 

Every component for cell assembly has to be there in large numbers at many places and functional when the individual units slide into the state of life. These multi-origin ideas have been around3 6 but did not fall on fertile ground, and what remained of these mavericks polyphyletic thoughts was wiped out by the discovery of the universality of the genetic code and the erroneous conclusions drawn from that observation. 

From time immemorial it has been thought that codes, or conventions, exist only in the mutable world of culture, while nature is governed by immutable laws. The discovery that a genetic code is at the very heart of life came therefore as a bolt from the blue. And people rushed... 

Electrophoresis experiments in glass tubes were reported as early as in the nineteenth century, but the first real breakthrough occurred in the first half of the twentieth century when the Swedish chemist Arne Tiselius applied free-solution electrophoresis—i.e moving boundary—to serum protein analysis, for which he later received the 1937 Nobel Prize [2], In less than two decades, just after the striking scientific discovery of the double-helical structure of DNA by Watson and Crick in 1953 [3] and the following unveiling of the genetic code, electrophoresis became a standard and indispensable tool in the field of modern... 

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