Ko te hanganga o te DNA me te RNA hanganga

Ki te whakaaro tatou ki te ahua o te rāpoi ngota pītauira rite reira tōrino miro, i hanga nei e mekameka polynucleotide rua nei e whiria i waenganui ia ratou, a wā kotahi a tawhio noa tetahi o ratou toki noa.

Tikanga, whakaaro te hanganga DNA i roto i te pūnaha tātari, ai rite te matua - he tino pūmau (hoki noa huru) tukanga interposition dezoksiribonukleozidmonofosfatov - dNMP, wae polynucleotide mekameka.

I roto i te kore-mutated piri mononucleotides pūtau here phosphodiester, ki a ratou ano katinga mekameka polynucleotide i rua ngā kōwhiringa mo te wāhi o ngā rōpū tūturu i te-mutunga 5'o te mekameka e te rōpū Phosphate, a kei roto i te Z'-mutunga iahiko te rōpū OH.

Ki te whakaaro tatou he rāpoi ngota arā, o rua ngā whenu, ko taua te hanganga DNA e ka antiparallel ki ia atu te mekameka polynucleotide. I roto i tenei ara iahiko puritia i roto i te hanganga taua ka waiho ki here hauwai e te tīariari i waenganui i nga turanga te-T ko GC, paparite, hāngai ki te tuaka matua o nga rāpoi ngota tōrino tika. Aua taunekeneke hydrophobic, kua hanga e i waenganui i nga turanga o te rāpoi ngota taua, whakarato pūmautanga puta noa te helix rua. Hoki te taua rāpoi ngota, te hanganga o DNA āhuatanga e kïnakitanga o mekameka polynucleotide, engari e kore e ratou tuakiri rite ratou hanganga nucleotide e faikehekehe.

I tua atu, ko te hanganga DNA whakaaro e, kia tuhia te reira e muingota ia takitahi te "Kikī" i roto i te tino ahurei, pūira motuhake. Kei roto ēnei pūira i te momo o te pūmua e hāngai ana ki te raupapa tino tautuhi o te hanganga DNA rāpoi ngota. E whakarōpūtia ēnei pūmua ki 2 kāwai: histones me pūmua negistony. I roto i te matatini ki te DNA karihi o te pūtau, ka karanga enei pūmua pūpūira.

Whakaahua i te hanganga o te DNA, kia tuhia te reira e ngā pūpūira o rima ngā momo o histones, te tiaki pai katoa e whakarato ana i te histones here rawa te kaha ki te DNA. Ko te matatini o histones me ngā rāpoi ngota DNA tautuhi wahi karapotia te 146 nucleotide takirua, te ähua, i roto i nei hanga nucleosomes.

Kei roto i te hanganga o te pūmua DNA muingota negistony tohu ngā momo o pūmua ture, e pā ana ki ngā raupapa DNA. Ano, rāpoi DNA tautoko ki te hanganga o whākōkī whakarato biosynthesis.

A tuatapapa i te hanganga o te DNA me te RNA i roto i te tātari pūnaha kia anake kia i te matatini, e te, ka whakaaro te hanganga o te DNA, he mea e tika ana ki te whakaaro i te hanganga me te RNA.

Ko tōna hanganga tuatahi, me te i roto i te take o te rāpoi ngota pītauira ko te interlace ribonukleozidmonofosfatov hātepe, te kupu, kia tangohia ki pūkete e, pērā DNA, momo katoa o RNA i tetahi anake mekameka o te polynucleotide. I roto i te hanganga o te rāpoi ngota RNA me ona whenu kotahi e hanga e, na ka karanga "napikeni" - spiralized koropiko e ko AU me turanga GC ka ähuareka roto i hauwai hononga.

Tikanga, ngā te rāpoi ngota pītauira toharite nui rawa e pā ana ki 150 takirua nucleotide millionov, me tona roa, ko te wha henimita. Ko tino ērā hoki te ako te tātari taiwhanga o taua rāpoi, no te mea i te mea e te tohanga o te kikokiko, e whangai ana i te rāpoi ngota ki te kia tino kongakonga a meinga nui iti i roto i te rahi. Hei whakakore i tenei rarua, i roto i te akoranga i te tikanga o PCR - whakahaere polymerase chain reaction, i roto i nei te tīpakongia synthesizing wāhanga takitahi o te rāpoi ngota pītauira, a ki te tohatoha i te rangahau e tika ana mo ona whatiwhatinga.