Imisebenzi ye-DNA kunye nesakhiwo sayo

Xa intliziyo iiseli abaphila eziphilayo imisebenzi ebalulekileyo imisebenzi ye Iipholima zebhayoloji, ii-asidi acid, iikhabhohayidrethi, ngeeproteni lipids. Biopolymers luqulathe monomers, izakhiwo, ezizizembiwa, eziquka initrogen, ioksijini, isalfure kunye phosphorus.

Ngenkulungwane ye-19, isifundo ngesakhiwo kwezinto lwaqaliswa, eyenza i iseli eziphilayo, kodwa umsebenzi DNA, iiprotheni, RNA, nesakhiwo labo ekugqibeleni wayezimisele kwinkulungwane yama-20.

Friedrich Miescher ngo-1868, owayengahlali kwiseli nuclei leukocytes phosphorous walibiza nukleina. Ke Richard Altman ngo-1889 kwafumaniseka ukuba le nto ibandakanya asidi ezizodwa kunye protini. Ngoko okokuqala waza weva ngalo elithi "nucleic". Noko ke, ukuba basungule umsebenzi nucleic wayesadla kude kude.

DNA - deoxyribonucleic acid - yeyona Iipholima inkulu eziphilayo owakhiwa ngayo monomers zamakhulu - deoxyribonucleotides. Kumafa yabo ngaphandle iswekile (deoxyribose), iquka iintlobo 4 nucleotides: adenine - A, thymidine - T, cytosine - C, guanine - G.

Ixesha lokuqala kwakusithiwa DNA nucleic acid imvelaphi yezilwanyana, ekubeni yayiyimini uyazimela thymus kwezilwanyana, kunye RNA iye ingadibani lwegciwane ingqolowa - nemifuno. Oku kwakukholelwa ukuba umahluko zengqo- phakathi kweentlanga iiseli afumaneka ekugqibeleni zaye teny nezilwanyana. Noko ke, phakathi kwinkulungwane yamashumi amabini bafumanisa ukuba RNA ne -DNA zifakiwe zonke iiseli.

Ngoko nangoko isakhiwo waqalisa ukufunda nucleic Erwin Chargaff, owathi ngo-1953 lwafumanisa ukuba nucleotides eziyinxalenye olufanayo igama acid ifomu ngababini kunye njalo engqongqo.

Umdibaniso usoloko uya pyrimidine kunye purine enye isiseko mnye, T = C, A = T. Oko kukuthi, adenine enebana thymidine kunye guanine - kunye cytosine.

Kwaye umsebenzi DNA Kubalulekile ukuba uqhagamshelwano kwimeko yokuqala ezinika hydrogen iipere ezi-2, kunye yesibini - ezintathu.

imithetho Chargaff wawungqina isiseko apho Watson kunye Crick wakha isakhiwo i-DNA Helix kabini.

Kule molecule, kwakunye iimolekyuli protein, ezahlukeneyo zaseprayimari, izakhiwo lesibini nelesithathu.

Ukuma ephambili - ulandelelwano linear of monomers ezikwi efanayo.

Kakade ke, xa uhlobo iDNA nomxokelelwane omnye lungenzeki, kodwa apha sithetha isakhiwo iphambili biopolymers, nto leyo ichaza zonke izakhiwo zawo.

isakhiwo Secondary - luphawu lwendawo le biopolymer. Kwimeko DNA le polynucleotide neentsontelo ezimbini, nganye kuzo ijijekileyo kwindawo kweleli elungileyo, kwaye bobabini ngaxeshanye ejijekileyo kwicala langasekunene malunga esqwini eqhelekileyo. Ezi amatyathanga ziyabanjwa ecaleni kwifuthe hydrogen nimanyane. Isakhiwo neliphezulu molekyuli DNA kweleli echazwe phambili.

Inyathelo omkhulu phambili yenziwe lokubhaqwa ukuba umsebenzi DNA kukudlulisela kunye nokugcinwa kolwazi yemfuza. DNA iqulathe inkqubo yezofuzo ye ubume iiprothini, ezithile ngoba umzimba ngamnye. Bona, kunye molekyuli RNA ukugqithisa ulwazi yemfuza ukusuka ephilayo ephilayo. I-DNA nayo linoxanduva lokumisela yemfuza. Bona inxaxheba kwiinkqubo umbhalo, ukuphindaphindeka translation, ngaloo ndlela kuqinisekiswe Yindibanisela iiprothini ezahlukeneyo.