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
New platinum compound shows promise in tumor cells
7 hours ago |
4.8 / 5 (4) |
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(PhysOrg.com) -- MIT chemists have developed a new platinum compound that is as powerful as the commonly used anticancer drug cisplatin but better able to destroy tumor cells.
Hitler skull fragment in Moscow authentic: FSB
Other Sciences / Archaeology & Fossils
8 hours ago |
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An officer with the Russian intelligence service the FSB on Monday dismissed a US report suggesting a fragment of Hitler's skull held in Moscow is actually from a woman, insisting their relic is genuine.
New hope for diagnosis and treatment of intractable pediatric brain tumors
12 hours ago |
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Scientists have discovered oncogenes capable of driving growth of normal human brain stem cells in a highly malignant pediatric brain tumor. The research, published by Cell Press in the December issue of the journal Cancer Ce ...
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 ...
Why we outlive our ape ancestors
Dec 02, 2009 |
4 / 5 (5) |
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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 ...
Grooving down the helix: Researchers show how proteins slide along DNA to carry out vital biological processes
Dec 03, 2009 |
4 / 5 (3) |
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(PhysOrg.com) -- A team of scientists has made a major step in understanding how molecules locate the genetic information in DNA that is necessary to carry out important biological processes.
Gene Testing In the Doctors Office
Nanotechnology / Bio & Medicine
Dec 02, 2009 |
5 / 5 (5) |
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(PhysOrg.com) -- A portable instrument manufactured by Nanosphere Inc. and recently approved by the FDA, can detect genetic variations in blood that alter the effectiveness of some drugs.
Some birds listen, instead of look, for mates
Dec 02, 2009 |
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Looks can be deceiving, but certain bird species have figured out that a voice can tell them most of what they need to know to find the right mate.
Kangaroos may hold skin cancer cure: study
Nov 30, 2009 |
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Kangaroos may provide the key to a potential treatment to prevent skin cancer, Australian scientists said Monday.
Biology of emergent Salmonella exposed
Nov 30, 2009 |
5 / 5 (1) |
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Researchers have characterised a new multi drug resistant strain of Salmonella Typhimurium that is causing life-threatening disease in Africa.
Understanding DNA Repair and Cancer
Dec 03, 2009 |
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(PhysOrg.com) -- A protein that plays a key role in copying DNA also plays a vital role in repairing breaks in it, UC Davis scientists have found. The work is helping researchers understand how cancer cells can resist radiation ...
2 heads better than 1 in new antibiotic method
Dec 03, 2009 |
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An antibiotic that binds to a well-established target in a novel and unexpected way could be the inspiration for designing new, more potent antibacterial drugs.
Researchers plan DNA sequencing for entire Pacific island
Dec 02, 2009 |
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(PhysOrg.com) -- University of Florida researchers are collecting marine invertebrates on the French Polynesian island of Moorea as part of a massive effort to inventory the DNA sequence of every living species ...
Discovery opens new avenues for treating devastating freshwater fish parasite, 'Ich'
Dec 02, 2009 |
4.8 / 5 (4) |
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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 ...
Illinois to poison canal in hopes of killing invasive carp
Dec 02, 2009 |
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The largest fish kill in Illinois history -- expected to net 100 tons of fish including, hopefully, some Asian carp -- is to start Wednesday south of Chicago in an attempt to make sure none of the feared carp make it past ...
