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
Faster, cheaper DNA sequencing method developed
Nanotechnology / Bio & Medicine
Dec 20, 2009 |
4.4 / 5 (27) |
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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 ...
World's smallest semiconductor laser heralds new era in optical science
Aug 30, 2009 |
4.8 / 5 (25) |
1
(PhysOrg.com) -- Researchers at the University of California, Berkeley, have reached a new milestone in laser physics by creating the world's smallest semiconductor laser, capable of generating visible light ...
Ancient penguin DNA raises doubts about accuracy of genetic dating techniques
Nov 10, 2009 |
4.7 / 5 (23) |
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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 ...
Carbon nanotubes could make efficient solar cells
Nanotechnology / Nanomaterials
Sep 10, 2009 |
5 / 5 (21) |
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(PhysOrg.com) -- Cornell researchers fabricated, tested and measured a simple solar cell called a photodiode, formed from an individual carbon nanotube.
Researchers Probe Links Between Modern Humans and Neanderthals
Sep 19, 2009 |
4.7 / 5 (20) |
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Which genes make us uniquely human? Scientists are looking at DNA in old bones to find out. The focus now is not so much on our own species, Homo sapiens. Instead, scientists are probing DNA in well-preserved pieces ...
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.
Humans spread out of Africa later
Other Sciences / Archaeology & Fossils
Sep 04, 2009 |
4.5 / 5 (18) |
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Modern humans spread out of Africa 20,000 years later than previously thought, according to new genetic research just published.
Scientists decipher the 3-D structure of the human genome
Oct 08, 2009 |
5 / 5 (16) |
1
(PhysOrg.com) -- Scientists have deciphered the three-dimensional structure of the human genome, paving the way for new insights into genomic function and expanding our understanding of how cellular DNA folds ...
Student sleuths using DNA reveal zoo of 95 species in NYC homes -- and new evidence of food fraud
Dec 28, 2009 |
5 / 5 (15) |
5
Two New York City high school students exploring their homes using the latest high-tech DNA analysis techniques were astonished to discover a veritable zoo of 95 animal species surrounding them, in everything ...
New Yorkers beware! New cockroach hits the Big Apple
Dec 24, 2009 |
4.1 / 5 (18) |
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New Yorkers are used to fighting each other for space, but there may be a new contender in town according to a Rockefeller study that appears to have uncovered a new species of cockroach.
What drives our genes? Researchers map the first complete human epigenome
Oct 14, 2009 |
4.8 / 5 (14) |
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Although the human genome sequence faithfully lists (almost) every single DNA base of the roughly 3 billion bases that make up a human genome, it doesn't tell biologists much about how its function is regulated. Now, researchers ...
Mummy's tooth yields DNA
Other Sciences / Archaeology & Fossils
Oct 22, 2009 |
4.6 / 5 (14) |
1
(PhysOrg.com) -- A four thousand year old Egyptian mummy's tooth has yielded its DNA to probing scientists.
Newly explored bacteria reveal some huge RNA surprises
Dec 02, 2009 |
4.9 / 5 (12) |
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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 ...
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, ...
The mammoths' swan song revised
Other Sciences / Archaeology & Fossils
Dec 14, 2009 |
4.4 / 5 (12) |
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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 ...
