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
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 ...
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.
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 ...
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 ...
Newly explored bacteria reveal some huge RNA surprises
9 hours ago |
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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 ...
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 ...
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 ...
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.
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 ...
Discovery opens new avenues for treating devastating freshwater fish parasite, 'Ich'
11 hours ago |
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Researchers from the University of Georgia College of Veterinary Medicine have made an "unexpected" dual discovery that could open new avenues for treating Ichthyophthirius multifiliis, or "Ich", a devastating ...
Scientists reveal how induced pluripotent stem cells differ from embryonic stem cells
Nov 05, 2009 |
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The same genes that are chemically altered during normal cell differentiation, as well as when normal cells become cancer cells, are also changed in stem cells that scientists derive from adult cells, according to new research ...
Why we outlive our ape ancestors
9 hours ago |
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In spite of their genetic similarity to humans, chimpanzees and great apes have maximum lifespans that rarely exceed 50 years. The difference, explains USC Davis School of Gerontology Professor Caleb Finch, is that as humans ...
Nanostructured Integrated Circuit Detects Type and Severity of Cancer
Nanotechnology / Bio & Medicine
Nov 03, 2009 |
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(PhysOrg.com) -- A team of investigators from the University of Toronto have used nanomaterials to develop an inexpensive microchip sensitive enough to quickly determine the type and severity of a patient's cancer so that ...
Petascale computing tools could provide deeper insight into genomic evolution
Technology / Computer Sciences
Nov 17, 2009 |
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Technological advances in high-throughput DNA sequencing have opened up the possibility of determining how living things are related by analyzing the ways in which their genes have been rearranged on chromosomes. ...
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 ...
