Deoxyribonucleic acid molecular structure

DMF, see Dimethylformamide DM SO, see Dimethyl sulfoxide DMT (dimethoxytrilyl ether), DNA synthesis and, 1114 DNA, see Deoxyribonucleic acid DNA fingerprinting, 1118-1119 reliability of, 1119 STR loci and, 1118 Dopamine, molecular model of. 930 Double bond, electronic structure of, 16... 

See also Deoxyribonucleic acid (DNA) base-pair sequencing of, 22 11 molecular structure of, 22 10 capillary electrophoresis, 4 636-637 chemical analysis of ancient, 5 750-751 contact print, 22 504 as a vaccine, 25 502-503... 

Nucleotides have a variety of roles in cellular metabolism. They are the energy currency in metabolic transactions, the essential chemical links in the response of cells to hormones and other extracellular stimuli, and the structural components of an array of enzyme cofactors and metabolic intermediates. And, last but certainly not least, they are the constituents of nucleic acids deoxyribonucleic acid (DNA) and ribonucleic acid (ENA), the molecular repositories of genetic information. The structure of every protein, and ultimately of every biomolecule and cellular component, is a product of information programmed into the nucleotide sequence of a cell s nucleic acids. The ability to store and transmit genetic information from one generation to the next is a fundamental condition for life. 

Harry Compton Crick, American scientist and Nobelisi (1962), proposed that ihe molecular structure of DNA is composed of deoxyribonucleic acid and proteins lhistones and high-molecular-weight proteins . These researchers proposed that the molecular structure of DNA is a double spiral helical chain. James H. White. American mathematician, shared the 1962 Nobel Prize. 

A typical molecular analysis of various micro-organisms is shown in Table 5.9U ) Most of the elemental composition of cells is found in three basic types of materials—proteins, nucleic acids and lipids. In Table 5.10, the molecular composi-tion of a bacterium is shown in more detail. Water is the major component of the cell and accounts for 80-90 per cent of the total weight, whilst proteins form the next most abundant group of materials and these have both structural and functional properties. Most of the protein present will be in the form of enzymes. Nucleic acids are found in various forms—ribonucleic acid (RNA) and deoxyribonucleic acid (DNA). Their primary function is the storage, transmission and... 

James D. Watson (1928-) and Francis H. C. Crick (1916- ) publish two landmark papers in the journal Nature. The papers are entitled Molecular structure of nucleic acids a structure for deoxyribose nucleic acid and Genetic implications of the structure of deoxyribonucleic acid. Watson and Crick propose a double helical model for DNA and call attention to the genetic implications of their model. Their model is based, in part, on the x-ray crystallographic work of Rosalind Franklin (1920-1958) and the biochemical work of Erwin Chargaff (1905- ). Their model explains how the genetic material is transmitted. 

During the past half a century, fundamental scientific discoveries have been aided by the symmetry concept. They have played a role in the continuing quest for establishing the system of fundamental particles [7], It is an area where symmetry breaking has played as important a role as symmetry. The most important biological discovery since Darwin s theory of evolution was the double helical structure of the matter of heredity, DNA, by Francis Crick and James D. Watson (Figure 1-2) [8], In addition to the translational symmetry of helices (see, Chapter 8), the molecular structure of deoxyribonucleic acid as a whole has C2 rotational symmetry in accordance with the complementary nature of its two antiparallel strands [9], The discovery of the double helix was as much a chemical discovery as it was important for biology, and lately, for the biomedical sciences. 

In deoxyribonucleic acid (DNA) the carbohydrate is 2-deoxy-D-ribose, while in ribonucleic acid (RNA) the carbohydrate residue is ribose. Three types of RNA were recognized, and they can be messenger RNA (mRNA), transfer RNA (tRNA), or ribosomal RNA (rRNA), which is the most abundant in cells. Values between 10 and 10 Dalton have been reported for the molecular weight of DNA, and the molecular weight is about 10 for rRNA, 10 for mRNA, and lOMor rRNA. The simplified structures of DNA and RNA are the following ... 

James Watson and Erancis Crick proposed the molecular structure of deoxyribonucleic acid (DNA) in 1952. Gathering a number of experimental findings on DNA, including x-ray diffraction patterns of DNA fibers, they proposed that DNA was a double-stranded helical molecule, with its hydrophobic bases occupying the interior of the molecule, and its hydrophilic... 

Watson JD and Crick FHC (1953) Molecular structure of nucleic acids. A structure for deoxyribonucleic acid. Nature 171 737—738. 

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