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
Enhancing arrest of cell growth to treat cancer in mice
Feb 08, 2010 |
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A team of researchers, led by Pier Paolo Pandolfi, at Beth Israel Deaconess Medical Center, Boston, has identified a new type of cellular senescence (i.e., irreversible arrest of cell growth) and determined a way to enhance ...
Turkeys domesticated not once, but twice
Other Sciences / Archaeology & Fossils
Feb 08, 2010 |
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Turkeys, the only domesticated animals from the New World that are now used globally, were actually domesticated twice -- once in Mesoamerica as was previously believed and once in what is now the southwestern ...
Scientists measure energy released from a virus during infection
Feb 05, 2010 |
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Within a virus's tiny exterior is a store of energy waiting to be unleashed. When the virus encounters a host cell, this pent-up energy is released, propelling the viral DNA into the cell and turning it into a virus factory. ...
An answer to another of life's big questions
Feb 05, 2010 |
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(PhysOrg.com) -- Monash University biochemists have found a critical piece in the evolutionary puzzle that explains how life on Earth evolved millions of centuries ago.
Michigan renews push to close Chicago ship locks
Feb 04, 2010 |
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(AP) -- Michigan wants the U.S. Supreme Court to reconsider its refusal to close Chicago-area shipping locks in hopes of keeping Asian carp out of the Great Lakes.
Scientists ID a protein that splices and dices genes
Feb 04, 2010 |
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A novel finding, described today on the Science Express Web site by teams from the National Cancer Institute, The University of Texas Health Science Center at San Antonio and the University of Toronto, offers a clue as to ...
Big book explores a small world: Professor debuts first complete guide to nanoscience
Feb 04, 2010 |
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Stuart Lindsay, Arizona State University Regents' professor and director of the Biodesign Institute's Center for Single Molecule Biophysics, has just released the first comprehensive guide to a tiny world ...
Moss helps chart the conquest of land by plants (w/ Video)
Feb 04, 2010 |
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(PhysOrg.com) -- Recent work at Washington University in St. Louis sheds light on one of the most important events in earth-history, the conquest of land by plants 480 million years ago.
Genes that regulate maternal inflammatory response, bacterial vaginosis and preterm birth related
Feb 04, 2010 |
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In a study to be presented today at the Society for Maternal-Fetal Medicine's (SMFM) annual meeting, The Pregnancy Meeting, in Chicago, researchers will show the use of haplotype tagging (hap-tag) single-nucleotide polymorphisms ...
Women With Variants in 'CLOCK' Gene Have Higher Risk of Breast Cancer
Feb 03, 2010 |
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(PhysOrg.com) -- A Yale University-led team of researchers has demonstrated for the first time that variants in a gene responsible for regulating the body’s circadian rhythm may lead to breast cancer. The ...
Scientists map epigenome of human stem cells during development
Feb 03, 2010 |
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Scientists at The Genome Institute of Singapore (GIS) and The Scripps Research Institute (TSRI) led an international effort to build a map that shows in detail how the human genome is modified during embryonic development.
Some morbidly obese people are missing genes
Feb 03, 2010 |
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A small but significant proportion of morbidly obese people are missing a section of their DNA, according to research published today in Nature. The authors of the study, from Imperial College London and ten other Europe ...
ARS researchers develop method to speed up breeding of scab-resistant barley cultivars
Feb 02, 2010 |
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Agricultural Research Service (ARS) scientists have developed an efficient and cost-effective method to speed up the breeding of scab-resistant barley cultivars, thus improving crop quality for small-grain breeders in the ...
Mechanical forces could affect gene expression
Feb 02, 2010 |
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(PhysOrg.com) -- University of Michigan researchers have shown that tension on DNA molecules can affect gene expression---the process at the heart of biological function that tells a cell what to do.
Scientists map out regulatory regions of genome, hot spots for diabetes genes
Feb 02, 2010 |
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Together with colleagues in Barcelona, researchers at the University of North Carolina at Chapel Hill have generated a complete map of the areas of the genome that control which genes are "turned on" or "off." The discovery, ...
