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
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 |
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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 |
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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.
Asian carp may have breached barrier protecting Lake Michigan
Nov 24, 2009 |
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Two feared species of Asian carp have zoomed beyond the $9 million electric barriers built to keep them out of Lake Michigan. Now, the only thing left between the carp and the Great Lakes is a lock and dam in southern Chicago.
Just like old times: Generating RNA molecules in water
Nov 20, 2009 |
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A key question in the origin of biological molecules like RNA and DNA is how they first came together billions of years ago from simple precursors. Now, in a study appearing in this week's Journal of Biological Chemistry, resear ...
Unknowlingly consuming endangered tuna
Nov 19, 2009 |
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While most of us would never willingly consume a highly endangered species, doing so might be as easy as plucking sushi from a bento box. New genetic detective work from the Sackler Institute for Comparative ...
Beyond genomics, biologists and engineers decode the next frontier
Nov 18, 2009 |
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(PhysOrg.com) -- A team of Princeton biologists and engineers has dramatically improved the speed and accuracy of measuring an enigmatic set of proteins that influences almost every aspect of how cells and ...
Research describes connections between Circadian and metabolic systems
Nov 17, 2009 |
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(PhysOrg.com) -- A paper by University of Notre Dame biologist Giles Duffield and a team of researchers offers new insights into a gene that plays a key role in modulating the body’s Circadian system and may ...
Two proteins act as molecular tailors in DNA repair
Nov 13, 2009 |
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(PhysOrg.com) -- On average, our cells encounter a very lethal form of DNA damage 10 times a day. Lucky for us, we have the capacity to repair each and every one of them. New research now reveals exactly how two well-known ...
New study describes connections between Circadian and metabolic systems
Nov 12, 2009 |
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A paper by University of Notre Dame biologist Giles Duffield and a team of researchers offers new insights into a gene that plays a key role in modulating the body's Circadian system and may also simultaneously modulate its ...
Microbial menagerie: Junk food binge alters community of microbes in the gut in less than a day
Nov 11, 2009 |
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(PhysOrg.com) -- Switching from a low-fat, plant-based diet to one high in fat and sugar alters the collection of microbes living in the gut in less than a day, with obesity-linked microbes suddenly thriving, according to ...
Researchers discover key to vital DNA, protein interaction
Nov 09, 2009 |
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(PhysOrg.com) -- A researcher at Iowa State University has discovered how a group of proteins from plant pathogenic bacteria interact with DNA in the plant cell, opening up the possibility for what the scientist ...
