DNA: Ìyàtọ̀ láàrin àwọn àtúnyẹ̀wò

DNA je is a long [[polymer|alarapupo]] gigun to je dida lati awo eyo to un tunde to nje [[nucleotide|nukleotidi]].<ref>{{cite book | last = Saenger | first = Wolfram | title = Principles of Nucleic Acid Structure | publisher = Springer-Verlag | location = New York | year = 1984 | isbn = 0-387-90762-9 }}</ref><ref name=Alberts>{{cite book |last=Alberts |first=Bruce | coauthors=Alexander Johnson, Julian Lewis, Martin Raff, Keith Roberts and Peter Walters |title=Molecular Biology of the Cell; Fourth Edition |publisher=Garland Science|year=2002 |location=New York and London |url=http://www.ncbi.nlm.nih.gov/books/bv.fcgi?call=bv.View..ShowTOC&rid=mboc4.TOC&depth=2 |isbn=0-8153-3218-1 |oclc=145080076 48122761 57023651 69932405}}</ref><ref name=Butler>{{cite book | author=Butler, John M. | year=2001 | title=Forensic DNA Typing | publisher= Elsevier | isbn=978-0-12-147951-0 | oclc=223032110 45406517}} pp. 14–15.</ref> Bo se koko je wiwari latowo [[James D. Watson]] ati [[Francis Crick]], idimu DNA gbogbo awon irueda ni awon ewon onilopo meji ti ikookan won lo ipo kanna ka, ti ikookan won si ni ite 34&nbsp;[[Ångström]] (3.4&nbsp;[[nanometre]]s) ati itanka 10&nbsp;[[Ångström]] (1.0&nbsp;[[nanometre]]s).<ref name=FWPUB>{{cite journal| author = Watson J.D. and Crick F.H.C. | pmid=13054692 | doi = 10.1038/171737a0 | url= http://www.nature.com/nature/dna50/watsoncrick.pdf | title=A Structure for Deoxyribose Nucleic Acid | journal=Nature | volume=171 | pages=737–738 | year=1953 | format=PDF| issue = 4356 | bibcode=1953Natur.171..737W}}</ref> Gegebi àgbékà miran se so, nigba to je wiwon nidu omiadalu pato kan, ewon DNA ni iwon 22 de 26&nbsp;[[Ångström]] ni fife (2.2 to 2.6&nbsp;[[nanometre]]s), be sini eyo nukleotidi kan ni iwon 3.3&nbsp;Å (0.33&nbsp;nm) ni gigun.<ref>{{cite journal |author=Mandelkern M, Elias J, Eden D, Crothers D |title=The dimensions of DNA in solution |journal=J Mol Biol |volume=152 |issue=1 |pages=153–61 |year=1981 |pmid=7338906 |doi=10.1016/0022-2836(81)90099-1}}</ref> Botilejepe ikookan eyo to untunde je kenkele, awon alarapupo DNA le je horo titobi to ni egbeegberun nukleotidi ninu. Fun apere, [[human chromosome|kromosomu omoniyan]] to tobijulo, kromosomu nomba 1, je bi 220 egbeegberun [[base pair|ipile meji]] ni gigun.<ref>{{cite journal |author=Gregory S |title=The DNA sequence and biological annotation of human chromosome 1 |journal=Nature |volume=441 |issue=7091 |pages=315–21 |year=2006 |pmid=16710414 | doi = 10.1038/nature04727 |last2=Barlow |first2=KF |last3=McLay |first3=KE |last4=Kaul |first4=R |last5=Swarbreck |first5=D |last6=Dunham |first6=A |last7=Scott |first7=CE |last8=Howe |first8=KL |last9=Woodfine |first9=K|bibcode = 2006Natur.441..315G }}</ref>

InNinu livingawon organismsagbarajo alaye DNA doeski notsaba usuallywa existbi ashoro akan single moleculesoso, but insteadsugbon asbi aawon pairhoro ofmeji moleculesti thatwon areje helddidimupo tightlyni togetherlilelile.<ref name=FWPUB>{{cite journal| author = Watson J.D. and Crick F.H.C. | pmid=13054692 | doi = 10.1038/171737a0 | url= http://www.nature.com/nature/dna50/watsoncrick.pdf | title=AÌdìmú Structurekan forfún DeoxyriboseKíkan NucleicNúkléù AcidDeọksiríbósì | journal=Nature | volume=171 | pages=737–738 | year=1953 | accessdate=4 May 2009|format=PDF| issue = 4356 | bibcode=1953Natur.171..737W}}</ref><ref name=berg>Berg J., Tymoczko J. and Stryer L. (2002) ''Biochemistry.'' W. H. Freeman and Company ISBN 0-7167-4955-6</ref> TheseAwon twomejeji longlorapo strandsbi entwineeka like vinesigi, inwon theri shape of abi [[double helix|alopo emeji]]. The nucleotide repeats containAwon bothnukleotidi theatun segmentni ofapa theigbaeyin backbone of the moleculehoro, whichto holdsmu theẹ̀wọ̀n chainna togetherpapo, andati aipilenukleu nucleobasekan, whichto interactsse withbasepo themo otheratinrin DNA strandmiran inninu thealopo helixna. AIpilenukleu nucleobase linkedkan to aso sugarpo ismo calledsuga akan lo nje [[nucleoside|nukleosidi]] andbe asini baseipile linkedkan to aso sugarmo andsuga onekan orati moremo phosphateikan groupstabi isopo calledadipo aoniyofosforu lo nje [[nucleotide|nukleotidi]]. PolymersAwon comprisingalarapupo multipleti linkedwon nucleotidesni opo nukleotidi ti wo so po mo ara won (asbi intinu DNA) arelo called anje [[polynucleotide|nukleotidipupo]].<ref name=IUPAC>[http://www.chem.qmul.ac.uk/iupac/misc/naabb.html Abbreviations and Symbols for Nucleic Acids, Polynucleotides and their Constituents] IUPAC-IUB Commission on Biochemical Nomenclature (CBN). Retrieved 03 January 2006.</ref>

TheIgbaeyin backboneatinrin ofDNA theje DNAdida strandlati isibi madeawon from alternatingìṣẹ́kù [[phosphate|oniyofosforu]] andati [[carbohydrate|sugarsuga]] residues.<ref name=Ghosh>{{cite journal |author=Ghosh A, Bansal M |title=A glossary of DNA structures from A to Z |journal=Acta Crystallogr D |volume=59 |issue=4 |pages=620–6 |year=2003 |pmid=12657780 |doi=10.1107/S0907444903003251}}</ref> TheSuga sugar ininu DNA isni [[deoxyribose|2-deoxyribosedeoksiribosi]], whichto isje asuga [[pentose|pentosi]] (five-[[carbon|karbonu]]-marun) sugar. The sugars are joined together by phosphate groups that form [[phosphodiester bond]]s between the third and fifth carbon [[atom]]s of adjacent sugar rings. These asymmetric [[covalent bond|bonds]] mean a strand of DNA has a direction. In a double helix the direction of the nucleotides in one strand is opposite to their direction in the other strand: the strands are ''antiparallel''. The asymmetric ends of DNA strands are called the [[directionality (molecular biology)|5′]] (''five prime'') and [[directionality (molecular biology)|3′]] (''three prime'') ends, with the 5' end having a terminal phosphate group and the 3' end a terminal hydroxyl group. One major difference between DNA and RNA is the sugar, with the 2-deoxyribose in DNA being replaced by the alternative pentose sugar [[ribose]] in RNA.<ref name=berg/>