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Henrietta Lacks (born Loretta Pleasant; August 1, 1920 – October 4, 1951) [2] was an African-American woman [5] whose cancer cells are the source of the HeLa cell line, the first immortalized human cell line [B] and one of the most important cell lines in medical research. An immortalized cell line reproduces indefinitely under specific ...
The double-helix model of DNA structure was first published in the journal Nature by James Watson and Francis Crick in 1953, [6] (X,Y,Z coordinates in 1954 [7]) based on the work of Rosalind Franklin and her student Raymond Gosling, who took the crucial X-ray diffraction image of DNA labeled as "Photo 51", [8] [9] and Maurice Wilkins, Alexander Stokes, and Herbert Wilson, [10] and base-pairing ...
The DNA double helix is stabilized primarily by two forces: hydrogen bonds between nucleotides and base-stacking interactions among aromatic nucleobases. [16] The four bases found in DNA are adenine (A), cytosine (C), guanine (G) and thymine (T).
Helix 2 and helix 3 form a so-called helix-turn-helix (HTH) structure, where the two alpha helices are connected by a short loop region. The N-terminal two helices of the homeodomain are antiparallel and the longer C-terminal helix is roughly perpendicular to the axes of the first two.
Bind to ssDNA and prevent the DNA double helix from re-annealing after DNA helicase unwinds it, thus maintaining the strand separation, and facilitating the synthesis of the new strand. Topoisomerase: Relaxes the DNA from its super-coiled nature. DNA gyrase: Relieves strain of unwinding by DNA helicase; this is a specific type of topoisomerase ...
In DNA double helix, the two strands of DNA are held together by hydrogen bonds. The nucleotides on one strand base pairs with the nucleotide on the other strand. The secondary structure is responsible for the shape that the nucleic acid assumes. The bases in the DNA are classified as purines and pyrimidines. The purines are adenine and guanine ...
Life Story (known as The Race for the Double Helix in the United States) is a 1987 television historical drama which depicts the progress toward, and the competition for, the discovery of the structure of DNA in the early 1950s.
The double helix is the dominant tertiary structure for biological DNA, and is also a possible structure for RNA. Three DNA conformations are believed to be found in nature, A-DNA, B-DNA, and Z-DNA. The "B" form described by James D. Watson and Francis Crick is believed to predominate in cells. [2]