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
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. ...
Scientists get to the root of ancient case of sour grapes
17 hours ago |
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(PhysOrg.com) -- Scientists in Cambridge have discovered that a lowly grape variety grown by peasants - but despised by noblemen - during the Middle Ages was the mother of many of today’s greatest grape varieties, ...
Researchers revise long-held theory of fruit-fly development
Dec 17, 2009 |
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For decades, science texts have told a simple and straightforward story about a particular protein—a transcription factor—that helps the embryo of the fruit fly, Drosophila melanogaster, pattern tissues in a m ...
Scientists crack gene code of common cancers
Dec 17, 2009 |
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Two common forms of cancer have been genetically mapped for the first time, British scientists announced, in a major breakthrough in understanding the diseases.
Scientists use DNA sequencing to attack lung cancer
Dec 16, 2009 |
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Aided by next-generation DNA sequencing technology, an international team of researchers has gained insights into how more than 60 carcinogens associated with cigarette smoke bind to and chemically modify human DNA, ultimately ...
The mammoths' swan song revised
Other Sciences / Archaeology & Fossils
Dec 14, 2009 |
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This is shown by samples of ancient DNA, analysed by an international team of research scientists under the leadership of Professor Eske Willerslev from Copenhagen University. Analyses of ancient DNA thereby ...
DNA needs a good editor: Researchers unravel the mysteries of DNA packaging
Dec 14, 2009 |
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Imagine a huge spool of film containing thousands of sequences of random scenes. Without a talented editor, a screening would have no meaning.
UNSW students sequence genome of the Wollemi Pine
Dec 17, 2009 |
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(PhysOrg.com) -- UNSW students have sequenced the chloroplast genome of the ancient Wollemi Pine - a world first that could reveal how a "dinosaur" of the tree kingdom survived 200 million years of shifting ...
TGen analysis identifies biomarkers for diabetic kidney failure
Dec 16, 2009 |
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Researchers using a DNA analysis tool developed by the Translational Genomics Research Institute (TGen) and UCLA have identified genetic markers that could help treat chronic kidney disease among diabetics.
Study: Looking young may mean living longer
Dec 14, 2009 |
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Those baby-faced people now have another reason to be smug: a new Danish study says looking young apparently means a longer life.
Study unveils potential genetic links to lung disease risk
Dec 14, 2009 |
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A new study involving data from more than 20,000 individuals has uncovered several DNA sequences linked to impaired pulmonary function. The research, an analysis that combined the results of several smaller studies, provides ...
Lawmakers seek emergency steps to halt Asian carp
Dec 12, 2009 |
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(AP) -- Members of Congress are demanding emergency action to prevent Asian carp from invading the Great Lakes and devastating their $7 billion fishery.
Free after 35 years: DNA clears Florida inmate
18 hours ago |
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(AP) -- For years, James Bain insisted he was home watching TV with his twin sister when a 9-year-old boy was kidnapped and raped.
Toward reading your own personal 'Book of Life'
Dec 16, 2009 |
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What secrets about your risk for diseases are written in your own personal "Book of Life" -- the 30,000 or so genes that make you you?
