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Nuclear DNA is a nucleic acid, a polymeric biomolecule or biopolymer, found in the nucleus of eukaryotic cells.Its structure is a double helix, with two strands wound around each other, a structure first described by Francis Crick and James D. Watson (1953) using data collected by Rosalind Franklin.
The two strands of DNA in a double helix can thus be pulled apart like a zipper, either by a mechanical force or high temperature. [27] As a result of this base pair complementarity, all the information in the double-stranded sequence of a DNA helix is duplicated on each strand, which is vital in DNA replication.
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 ...
Initiation of eukaryotic DNA replication is the first stage of DNA synthesis where the DNA double helix is unwound and an initial priming event by DNA polymerase α occurs on the leading strand. The priming event on the lagging strand establishes a replication fork.
B-DNA base pairs are nearly perpendicular to the helix axis. The sugar pucker which determines the shape of the a-helix, whether the helix will exist in the A-form or in the B-form, occurs at the C2'-endo. [13] A-DNA, is a form of the DNA duplex observed under dehydrating conditions. It is shorter and wider than B-DNA.
DNA replication also works by using a DNA template, the DNA double helix unwinds during replication, exposing unpaired bases for new nucleotides to hydrogen bond to. Gene synthesis, however, does not require a DNA template and genes are assembled de novo. DNA synthesis occurs in all eukaryotes and prokaryotes, as well as some viruses. The ...
The double helix is an important tertiary structure in nucleic acid molecules which is intimately connected with the molecule's secondary structure. A double helix is formed by regions of many consecutive base pairs. The nucleic acid double helix is a spiral polymer, usually right-handed, containing two nucleotide strands which base pair together.
Eukaryotic genomes are composed of one or more linear DNA chromosomes. The number of chromosomes varies widely from Jack jumper ants and an asexual nemotode, [28] which each have only one pair, to a fern species that has 720 pairs. [29] It is surprising the amount of DNA that eukaryotic genomes contain compared to other genomes.