Metadata
Author: langbot
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English[en]
Deoxyribonucleic acid (/diːˈɒksɪˌraɪboʊnjuːˌkliːɪk) DNA is a polymer composed of two polynucleotide chains that coil around each other to form a double helix carrying genetic instructions for the development, functioning, growth and reproduction of all known organisms and many viruses. DNA and ribonucleic acid (RNA) are nucleic acids. Alongside proteins, lipids and complex carbohydrates (polysaccharides), nucleic acids are one of the four major types of macromolecules that are essential for all known forms of life. The two DNA strands are known as polynucleotides as they are composed of simpler monomeric units called nucleotides.[2][3] Each nucleotide is composed of one of four nitrogen-containing nucleobases (cytosine [C], guanine [G], adenine [A] or thymine [T]), a sugar called deoxyribose, and a phosphate group. The nucleotides are joined to one another in a chain by covalent bonds (known as the phospho-diester linkage) between the sugar of one nucleotide and the phosphate of the next, resulting in an alternating sugar-phosphate backbone. The nitrogenous bases of the two separate polynucleotide strands are bound together, according to base pairing rules (A with T and C with G), with hydrogen bonds to make double-stranded DNA. The complementary nitrogenous bases are divided into two groups, pyrimidines and purines. In DNA, the pyrimidines are thymine and cytosine; the purines are adenine and guanine. Both strands of double-stranded DNA store the same biological information. This information is replicated when the two strands separate. A large part of DNA (more than 98% for humans) is non-coding, meaning that these sections do not serve as patterns for protein sequences. The two strands of DNA run in opposite directions to each other and are thus antiparallel. Attached to each sugar is one of four types of nucleobases (or bases). It is the sequence of these four nucleobases along the backbone that encodes genetic information. RNA strands are created using DNA strands as a template in a process called transcription, where DNA bases are exchanged for their corresponding bases except in the case of thymine (T), for which RNA substitutes uracil (U).[4] Under the genetic code, these RNA strands specify the sequence of amino acids within proteins in a process called translation. Within eukaryotic cells, DNA is organized into long structures called chromosomes. Before typical cell division, these chromosomes are duplicated in the process of DNA replication, providing a complete set of chromosomes for each daughter cell. Eukaryotic organisms (animals, plants, fungi and protists) store most of their DNA inside the cell nucleus as nuclear DNA, and some in the mitochondria as mitochondrial DNA or in chloroplasts as chloroplast DNA.[5] In contrast, prokaryotes (bacteria and archaea) store their DNA only in the cytoplasm, in circular chromosomes. Within eukaryotic chromosomes, chromatin proteins, such as histones, compact and organize DNA. These compacting structures guide the interactions between DNA and other proteins, helping control which parts of the DNA are transcribed.
Cornish[kw]
Molekulen (polymer) yw TDN po DNA, hemm yw trenken dhioksiribonukleyek, a gomprehend kedhlow eritys pub tra byw, an kod genynnek. Gwrys yw TDN a'n elvennow karbon, hidrojen, oksyjen, fosforos ha nitrojen. War-barth ha RNA, onan yw a'n trenkennow nukleyek. Klass nucleic acids, bewbolymer, rann nucleus, mitochondrion, genome, nucleosome, DNA binding, DNA metabolic process, DNA catabolic process, DNA biosynthetic process, DNA dephosphorylation, DNA transport, DNA transmembrane transporter activity, protein-DNA-RNA complex, protein-DNA complex, DNA import into cell involved in transformation. Synsys ynno/i polynucleotide, nucleotides. Molekulen (polymer) yw TDN po DNA, hemm yw trenken dhioksiribonukleyek, a gomprehend kedhlow eritys pub tra byw, an kod genynnek. Gwrys yw TDN a'n elvennow karbon, hidrojen, oksyjen, fosforos ha nitrojen. War-barth ha RNA, onan yw a'n trenkennow nukleyek. Kesweyth TDN (troyll dhewblek) Kesweyth DNA[golegi | pennfenten] Diskudhys veu TDN gans Friedrisch Miescher yn 1869 heb ev dhe gonvedhes hy forpos. Kesweyth TDN a veu diskudhys gans James Watson ha Francis Crick, war-barth ha Maurice Wilkins yn 1953. Yma diw gadon a nukleyotid gans an TDN. Nukleyotid yw molekulen le gwrys a sugra dioksiribos, sel nitrojenus ha bagas fosfat. An dhiw gadon a nukleyotidow a furv troyll dhewblek, ha synsys yw an dhiw war-barth gans kevrennow hidrojen a jun selyow an dhiw gadon yn koplow. Adenin (A), Thymin (T), Gwanin (G) ha Cytosin (C) yw peder sel an TDN. Adenin a jun pub tro gans Thymin dre dhiw gevren hidrojen, ha Gwanin pub tro gans Cytosin dre deyr kevren hidrojen. Rynnys yw an selyow dhe dhew vagas, pyramidinow (thymin ha cytosin) ha purinow (Adenin ha Gwanin). Koplow an selyow a dheu yn bagasow a dri (kod tryflek) dhe furvya trenken amino. Kemmys ha 20 trenken amino dyffrans a yll furvya, trenkennow yw komprehendys yn protinyow. Hemm a styr bos kedhlow drehevel protinyow komprehendys yn TDN. An TDN a yll treusskrifa an kedhlow ma rag gul protinyow yn ribosomow an kell. Dewblekheans TDN[golegi | pennfenten] An TDN a yll dewblekhe (duplicate) hy honan der usya ensaymow ha molekulennow treusperthi arbennik. Rag gul henna, an ensaym a wra ranna an TDN dhe'n dhew nukleyotid ha kettermyn pub nukleyotid a dhalleth askorra nukleyotid nowydh. Wosa gorfenna an argerdh ma, yma diw TDN nowydh, pubonan gans unn nukleyotid koth hag unn nukleyotid nowydh. Kammgemeryansow dewblekhe a gaws treylyansow.