Yintoni i-DNA, yintoni imisebenzi yayo nokubaluleka kwezinto eziphilayo

I-DNA yi- deoxyribonucleic acid, eqinisekisa ukugcinwa nokudluliselwa kolwazi lwezofuzo. Ngokwakheko ulwazi malunga nesakhiwo seRNA kunye nazo zonke iiprotheni zomzimba zifakwe nge-encrypted. Esi sakhiwo savulwa yiSwitzerland I.Mischler ngo-1869.

Ekuqaleni, izakhiwo zangempela zeDNA zaziwa. Kwakukholelwa ukuba wayejongene nokulondolozwa kwe-phosphorus emzimbeni, kwaye ingcaciso yakhe yayingaziwa nakwimpahla yakhe, njengokuba iiprotheni zithathwa njengabaphathi beenkcukacha zenkcubeko. Ngomnyaka we-1944, emva kweluhlu lwezilingo zokuguqulwa kweebhaktheriya, kwacaciswa ukuba i-DNA enjalo, kunye nemisebenzi yayo eyintloko ichongiwe. Emva kowe-1952, ulwazi malunga nale molekyuli lwandise - lwaziwa ukuba ngumphathi ophezulu wenkcazelo malunga nesakhiwo se-genotype (iqoqo lezakhi zemizimba emzimbeni), kodwa ngelo xesha akukho nto yaziwa malunga nesakhiwo sayo, isakhiwo se- DNA asizange sichazwe.

Isakhiwo sayo seemodeli saqalwa ngo-1953 nguYames Watson noFrancis Crick. Bazimisele ukuba i-DNA iyimodyuli ngohlobo lwe-helix ephindwe kabini, equkethe amaqela e-deoxyribose kunye ne-phosphate, ebopha kwiziseko ze-nitrogen-adenine, i-cytosine, i-guanine kunye ne-thymine.

Kufuneka kuqatshelwe ukuba ukudibanisa kwezi ziseko zine-order ecacileyo kakuhle-i-adenine ibophezela kuphela kwi-thymine, kunye ne-guanine kunye ne-cytosine, eqinisekisa ukuzenzeka ngokuchanekileyo kunye nokuchaneka kwe-molecule ye-DNA ngokwemigaqo yokuhambelanisa enye yentombi yayo.

Ingcaciso ecacileyo enjalo yesakhiwo se-molecular yenza ukuba kube lula ukuqonda ukuba yintoni isakhiwo se-DNA esilondoloza ikhowudi yezofuzo kwaye isiseko sobunzima bezinto eziphilayo, kuquka i-eukaryot kunye nezinye iigciwane.

I-genetic code is stored in the form of certain nucleotide. Ngaloo ndlela, nganye i-amino acid yeprotheni ifakwe kwii-nucleotide ezintathu, kwaye ukulandelelana kwama-acids yi-gene.

Naluphi na utshintsho kwisakhiwo se-DNA, kukho iinguqu okanye ukuguquka kwemfuyo. Ukutshintshwa kwenguqu eguquguqukayo kubandakanya ukuphulwa kwesakhiwo se-molecular, esingafunyanwa lula ngokuhlaziywa kwe-biochemical okanye hybridological. Ukuguquka kwe-Gene kwenzeka xa ulandelelwano lwe-nucleotides luguquka, oluyimiphumo yeenkqubo ezifana nokutshintshwa, ukuguqulwa, ukufakwa okanye ukulahlekelwa ngamabini ahlukeneyo eziseko ze-nitrogen eziphazamisa ukusebenza kunye neepropati ze-DNA.

Ukuba ezo zinguqu zengqungquthela zikhokelela ekuphambukeni kweendawo ezibalulekileyo ze-polypeptide, ngoko ukuphulwa okukhulu kunokuba kwenzeke emzimbeni, okwenzela kuqala ukuphulwa kophuhliso lwezinto eziphilayo, kodwa nokufa kwazo. Ngaloo ndlela, utshintsho luya kwenzeka nangona uphuhliso lwentsana, obangela ukuzalwa kwabantwana abafileyo okanye abangenakusebenza. Ukongezelela, ukuphulwa okunjalo kuyisiseko seengxaki ezingaphantsi komntwana ezingasasazwa kwizizukulwana ezalandelayo.

Ukufingqa oku ngasentla, sinokugqiba ukuba i-DNA enjalo ibaluleke kakhulu kwisakhiwo se-genetic ulwazi, eyona nto iphambili ye-chromosomes. Ukongeza, i-DNA yindidi ejongene nokuzaliswa kolwazi lokufa kunye nokusebenza kwezinto eziphilayo.