Search results
Results from the WOW.Com Content Network
In molecular biology, the term double helix [1] refers to the structure formed by double-stranded molecules of nucleic acids such as DNA. The double helical structure of a nucleic acid complex arises as a consequence of its secondary structure , and is a fundamental component in determining its tertiary structure .
A single-stranded non-circular DNA molecule has two non-identical ends, the 3' end and the 5' end (usually pronounced "three prime end" and "five prime end"). The numbers refer to the numbering of carbon atoms in the deoxyribose, which is a sugar forming an important part of the backbone of the DNA molecule. In the backbone of DNA the 5' carbon ...
Here, the single-stranded DNA curls around in a long circle stabilized by telomere-binding proteins. [68] At the very end of the T-loop, the single-stranded telomere DNA is held onto a region of double-stranded DNA by the telomere strand disrupting the double-helical DNA and base pairing to one of the two strands.
In most cases, naturally occurring DNA molecules are double-stranded and RNA molecules are single-stranded. [19] There are numerous exceptions, however—some viruses have genomes made of double-stranded RNA and other viruses have single-stranded DNA genomes, [20] and, in some circumstances, nucleic acid structures with three or four strands ...
DNA is made up of a double helix of two complementary strands. DNA is often called double helix. The double helix describes the appearance of a double-stranded DNA which is thus composed of two linear strands that run opposite to each other and twist together. [6] During replication, these strands are separated.
The chemical structure of DNA is insufficient to understand the complexity of the 3D structures of DNA. In contrast, animated molecular models allow one to visually explore the three-dimensional (3D) structure of DNA. The DNA model shown (far right) is a space-filling, or CPK, model of the DNA double helix. Animated molecular models, such as ...
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 ...
Other advances in molecular biology stemming from the discovery of the DNA double helix eventually led to ways to sequence genes. James Watson directed the Human Genome Project at the National Institutes of Health. [7] The ability to sequence and manipulate DNA is now central to the biotechnology industry and modern medicine.