CHIASMUS IN ART AND TEXT

2013 ◽  
Vol 60 (1) ◽  
pp. 50-88
Author(s):  
Edmund Thomas
Keyword(s):  
Molecular Structure ◽  
Twentieth Century ◽  
Nucleic Acid ◽  
Nucleic Acids ◽  
Double Helix ◽  
Scientific Article ◽  
Deoxyribose Nucleic Acid ◽  
Francis Crick

Sixty years ago, on 25 April 1953, probably the most influential scientific article of the twentieth century appeared. Its uninviting title, ‘Molecular Structure of Nucleic Acids: A Structure for Deoxyribose Nucleic Acid’, concealed the revolutionary discovery by the molecular biologists James Watson and Francis Crick of the structure of what became known as ‘the molecule of life’. The ‘radically different structure’ that they proposed for the salt of deoxyribose nucleic acid (DNA) had ‘two helical chains each coiled round the same axis’. ‘Both chains’, they wrote, ‘follow right-handed helices, but owing to the dyad the sequences of the atoms in the two chains run in opposite directions.’ When Bruno J. Strasser asked in the same journal fifty years later ‘Who cares about the double helix?’, he answered that it marked ‘an age of (lost) innocence, when youth, intelligence and self-assurance were sufficient to make great discoveries in science’.

Molecular Structure of Nucleic Acids: A Structure for Deoxyribose Nucleic Acid

Nature ◽  
1953 ◽  
Vol 171 (4356) ◽  
pp. 737-738 ◽  
Author(s):  
J. D. WATSON ◽  
F. H. C. CRICK
Keyword(s):  
Molecular Structure ◽  
Nucleic Acid ◽  
Nucleic Acids ◽  
Deoxyribose Nucleic Acid

scholarly journals Molecular Structure of Nucleic Acids: A Structure for Deoxyribose Nucleic Acid

Nature ◽  
1974 ◽  
Vol 248 (5451) ◽  
pp. 765-765 ◽  
Author(s):  
J. D. WATSON ◽  
F. H. C. CRICK
Keyword(s):  
Molecular Structure ◽  
Nucleic Acid ◽  
Nucleic Acids ◽  
Deoxyribose Nucleic Acid

Mercury Electrodes in Nucleic Acid Electrochemistry: Sensitive Analytical Tools and Probes of DNA Structure. A Review

2004 ◽  
Vol 69 (4) ◽  
pp. 715-747 ◽  
Author(s):  
Miroslav Fojta
Keyword(s):  
Nucleic Acid ◽  
Nucleic Acids ◽  
Double Helix ◽  
Dna Structure ◽  
Electrochemical Analysis ◽  
Label Free ◽  
Helix Formation ◽  
Mercury Electrodes ◽  
Dna Strand ◽  
Dna Double Helix

This review is devoted to applications of mercury electrodes in the electrochemical analysis of nucleic acids and in studies of DNA structure and interactions. At the mercury electrodes, nucleic acids yield faradaic signals due to redox processes involving adenine, cytosine and guanine residues, and tensammetric signals due to adsorption/desorption of polynucleotide chains at the electrode surface. Some of these signals are highly sensitive to DNA structure, providing information about conformation changes of the DNA double helix, formation of DNA strand breaks as well as covalent or non-covalent DNA interactions with small molecules (including genotoxic agents, drugs, etc.). Measurements at mercury electrodes allow for determination of small quantities of unmodified or electrochemically labeled nucleic acids. DNA-modified mercury electrodes have been used as biodetectors for DNA damaging agents or as detection electrodes in DNA hybridization assays. Mercury film and solid amalgam electrodes possess similar features in the nucleic acid analysis to mercury drop electrodes. On the contrary, intrinsic (label-free) DNA electrochemical responses at other (non-mercury) solid electrodes cannot provide information about small changes of the DNA structure. A review with 188 references.

Self-assembled Materials Containing Complementary Nucleobase Molecular Recognition

2008 ◽  
Vol 1094 ◽  
Author(s):  
Wirasak Smitthipong ◽  
Arkadiusz Chworos ◽  
Brian Lin ◽  
Thorsten Neumann ◽  
Surekha Gajria ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Mechanical Properties ◽  
Nucleic Acid ◽  
Nucleic Acids ◽  
X Ray ◽  
Transparent Films ◽  
X Ray Scattering ◽  
Counter Ions ◽  
Self Assembled ◽  
Cationic Amphiphile

AbstractHere we report the nucleic acid/cationic amphiphile based-materials in which we exchange the counter-ions of the polyanionic backbone of the nucleic acids with the cationic amphiphiles to form self-assembled transparent films with the thickness of several microns. Predominantly, single stranded poly(A), poly(U) and double stranded poly(AU) were employed for these studies. Small-angle X-ray scattering (SAXS) experiments suggested lamellar-like structure for all the film samples. However, the molecule length as well as the molecular structure of nucleic acids can affect the topology and mechanical properties of these films. Complementary base-paring of poly(AU) is reported here with comparison to poly(A) and poly(U) complexes.

The Messy Story behind the Most Beautiful Experiment in Biology

2017 ◽  
Author(s):  
Douglas Allchin
Keyword(s):  
Molecular Structure ◽  
Genetic Information ◽  
Double Helix ◽  
Genetic Material ◽  
The Other ◽  
Aesthetic Response ◽  
Dna Molecule ◽  
Francis Crick ◽  
History Of ◽  
Complete Set

“The most beautiful experiment in biology.” That was how John Cairns described it: the 1958 experiment that showed how the genetic material, DNA, replicates. The work is still widely celebrated, sometimes in introductory biology textbooks. This esteemed experiment by Matt Meselson and Frank Stahl (described more fully below) and others like it reflect an ideal in science, one marked by an intuitive aesthetic response. The test was simple. The results were clear. The method and reasoning seemed obvious. Theory and evidence complemented each other elegantly. That seems to be how science works—or should work. However, this view of biology, so common as to be beyond question—another sacred bovine?—can be misleading. Appearances can be deceptive. Delving into the history of this now-famous experiment fosters a very different image. Behind the apparent simplicity hides extraordinary—and fascinating—complexity. A glimpse of the messy world of investigation indicates how science really happens, quite apart from the tidy scientific method that one finds in standard textbooks. Ultimately, the messy story behind the most beautiful experiment in biology offers a quite different, and deeply informative, way to appreciate science. The experiment developed from a puzzle about how DNA, the genetic molecule, replicates. In 1953 James Watson and Francis Crick, building on data from Rosalind Franklin and Maurice Wilkins, presented a model of DNA’s molecular structure. It was two threads that coiled around each other, they claimed. Like two intertwined strands of rope. That double helix model has since been widely celebrated and inspired much art. But how did the DNA molecule replicate? When any cell divides, each new cell receives a complete set of information. Duplicate copies of DNA are assembled. Watson and Crick had only hinted at how that might occur. The genetic information was a sequence of units, called nucleotides, that bridged the two strands. They occurred in pairs. The shapes in each pair were complementary. So the shape of one side would determine which missing base would pair on the other.

Molecular Structure of Deoxyribose Nucleic Acid and Nucleoprotein

Nature ◽  
1955 ◽  
Vol 175 (4463) ◽  
pp. 834-838 ◽  
Author(s):  
M. FEUGHELMAN ◽  
R. LANGRIDGE ◽  
W. E. SEEDS ◽  
A. R. STOKES ◽  
H. R. WILSON ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Nucleic Acid ◽  
Deoxyribose Nucleic Acid

Nucleic Acid Molecules Prepared by Monolayer Techniques

1972 ◽  
Vol 30 ◽  
pp. 178-179
Author(s):  
Dimitrij Lang
Keyword(s):  
Electron Microscopy ◽  
Standard Deviation ◽  
Nucleic Acid ◽  
Cytochrome C ◽  
Nucleic Acids ◽  
Contour Length ◽  
Sample Standard Deviation ◽  
Molecular Weights ◽  
Length Measurements ◽  
Protein Monolayer

The success of the protein monolayer technique for electron microscopy of individual DNA molecules is based on the prevention of aggregation and orientation of the molecules during drying on specimen grids. DNA adsorbs first to a surface-denatured, insoluble cytochrome c monolayer which is then transferred to grids, without major distortion, by touching. Fig. 1 shows three basic procedures which, modified or not, permit the study of various important properties of nucleic acids, either in concert with other methods or exclusively:1) Molecular weights relative to DNA standards as well as number distributions of molecular weights can be obtained from contour length measurements with a sample standard deviation between 1 and 4%.

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