Related topics: protein , genes , genome , rna , genetic code
DNA
hideDeoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms and some viruses. The main role of DNA molecules is the long-term storage of information. DNA is often compared to a set of blueprints or a recipe, or a code, since it contains the instructions needed to construct other components of cells, such as proteins and RNA molecules. The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in regulating the use of this genetic information.
Chemically, DNA consists of two long polymers of simple units called nucleotides, with backbones made of sugars and phosphate groups joined by ester bonds. These two strands run in opposite directions to each other and are therefore anti-parallel. Attached to each sugar is one of four types of molecules called bases. It is the sequence of these four bases along the backbone that encodes information. This information is read using the genetic code, which specifies the sequence of the amino acids within proteins. The code is read by copying stretches of DNA into the related nucleic acid RNA, in a process called transcription.
Within cells, DNA is organized into X-shaped structures called chromosomes. These chromosomes are duplicated before cells divide, in a process called DNA replication. Eukaryotic organisms (animals, plants, fungi, and protists) store most of their DNA inside the cell nucleus and some of their DNA in the mitochondria (animals and plants) and chloroplasts (plants only). Prokaryotes (bacteria and archaea) however, store their DNA in the cell's cytoplasm. Within the chromosomes, chromatin proteins such as histones compact and organize DNA. These compact structures guide the interactions between DNA and other proteins, helping control which parts of the DNA are transcribed.
For more information about DNA, read the full article at
Wikipedia.
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News tagged with dna
Scientists Build Nanostructures out of Single DNA Strands
Nanotechnology / Bio & Medicine
Sep 08, 2009 |
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(PhysOrg.com) -- With its unique double-helical structure, DNA has the ability to be used as a programmable building material to construct designer nanoscale architectures. Complex DNA architectures could ...
Faster, cheaper DNA sequencing method developed
Nanotechnology / Bio & Medicine
Dec 20, 2009 |
4.4 / 5 (25) |
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(PhysOrg.com) -- Boston University biomedical engineers have devised a method for making future genome sequencing faster and cheaper by dramatically reducing the amount of DNA required, thus eliminating the ...
Lung cancer and melanoma laid bare: First comprehensive analysis of two cancer genomes
Dec 16, 2009 |
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Research teams led by the Wellcome Trust Sanger Institute announce the first comprehensive analyses of cancer genomes. All cancers are caused by mutations in the DNA of cancer cells which are acquired during a person's lifetime. ...
Introns: A mystery renewed
Dec 10, 2009 |
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The sequences of nonsense DNA that interrupt genes could be far more important to the evolution of genomes than previously thought, according to a recent Science report by Indiana University Bloomington and ...
Newly explored bacteria reveal some huge RNA surprises
Dec 02, 2009 |
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(PhysOrg.com) -- Yale University researchers have found very large RNA structures within previously unstudied bacteria that appear crucial to basic biological functions such as helping viruses infect cells ...
Reference Genome of Maize Published (w/ Podcast)
Nov 19, 2009 |
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(PhysOrg.com) -- A four-year, multi-institutional effort co-led by three Cold Spring Harbor Laboratory scientists culminated today in publication of a landmark series of papers in the journal Science reveal ...
Africa's rarest monkey had an intriguing sexual past, DNA study confirms
Nov 11, 2009 |
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The most extensive DNA study to-date of Africa's rarest monkey reveals that the species had an intriguing sexual past. Of the last two remaining populations of the recently discovered kipunji, one population ...
Antarctic lake home to diverse community of viruses
Nov 11, 2009 |
4.9 / 5 (17) |
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(PhysOrg.com) -- A study of the genetic structure of viruses in an Antarctic lake has revealed an astonishing genetic richness in the large number of viral families discovered.
Ancient penguin DNA raises doubts about accuracy of genetic dating techniques
Nov 10, 2009 |
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Penguins that died 44,000 years ago in Antarctica have provided extraordinary frozen DNA samples that challenge the accuracy of traditional genetic aging measurements, and suggest those approaches have been ...
Nanoparticles may cause DNA damage across a cellular barrier
Nanotechnology / Bio & Medicine
Nov 05, 2009 |
4.3 / 5 (9) |
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(PhysOrg.com) -- Scientists have shown in the laboratory that metal nanoparticles damaged the DNA in cells on the other side of a cellular barrier. The research, by the University of Bristol, is published ...
Researchers use drug-radiation combo to eradicate lung cancer
Oct 29, 2009 |
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Researchers at UT Southwestern Medical Center have eliminated non-small cell lung (NSCL) cancer in mice by using an investigative drug called BEZ235 in combination with low-dose radiation.
A solution to Darwin's 'mystery of the mysteries' emerges from the dark matter of the genome
Oct 26, 2009 |
4.2 / 5 (14) |
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Biological species are often defined on the basis of reproductive isolation. Ever since Darwin pointed out his difficulty in explaining why crosses between two species often yield sterile or inviable progeny (for instance, ...
Mummy's tooth yields DNA
Other Sciences / Archaeology & Fossils
Oct 22, 2009 |
4.6 / 5 (14) |
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(PhysOrg.com) -- A four thousand year old Egyptian mummy's tooth has yielded its DNA to probing scientists.
Study surprise yields new target for assessing genes linked to autism
Oct 21, 2009 |
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Researchers at Duke University Medical Center have uncovered a new genetic signature that correlates strongly with autism and which doesn't involve changes to the DNA sequence itself. Rather, the changes are in the way the ...
Loss of Tumor-Suppressor and DNA-Maintenance Proteins Causes Tissue Demise, Study Finds
Oct 15, 2009 |
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(PhysOrg.com) -- A study published in the October issue of Nature Genetics demonstrates that loss of the tumor-suppressor protein p53, coupled with elimination of the DNA-maintenance protein ATR, severely disrup ...
