Sechivako DNA uye RNA mamiriro

Kana isu fungidzira nechitarisiko Morekuru reDNA afanane yakakoswa zononoka, icho chakaumbwa nemakomo maviri ngetani polynucleotide ayo vakamonyanisa pakati pachavo uye panguva imwe chete kumativi rimwe ravaigona namasanhu.

Kazhinji, DNA mamiriro ichaongororwa mukati nenyaya hurongwa, sezvamakaropafadzwa sezvo huru - ndekwokuda yatarwa (nokuti kuipa ezvinhu) nzira interposition dezoksiribonukleozidmonofosfatov - dNMP, zvinoumba polynucleotide cheni.

In non-mutated sero mononucleotides vakabatana phosphodiester zvisungo, pachavo kuvhara polynucleotide ngetani mbiri zvokusarudza kuti nzvimbo mapoka chaiwo panguva 5'-kuguma cheni ari phosphate boka, uye OH boka iri Z'-mugumo redunhu.

Kana tikaongorora morekuru rine tambo mbiri, kuti DNA mamiriro akadaro kuti polynucleotide cheni achava antiparallel kune mumwe. In redunhu ichi rakaramba ari maumbirwo akadaro achava nokuda rehydrogen zvisungo kuripo pakati pezvingoro A-T uye GC, coplanar, perpendicular kune huru akabatana ari mamorekuru zononoka. hydrophobic kwavatori avo, vari yakaumbwa pakati nezvigadziko morekuru yakadaro, zvinopa kutsiga mhiri kaviri akamonyoroka. Nokuti vakadaro Morekuru, sechivako DNA hwokuratidza complementarity pamusoro polynucleotide necheni, asi kwete kuzivikanwa avo nucleotide sezvamunoita anosiyana.

Uyezve, tichifunga kuti ari DNA mamiriro, zvinofanira kucherechedzwa kuti mumwe nomumwe Morekuru ari "yakazara" ari zvakasimba akasiyana, wakaparadzaniswa chromosome. okutodza izvi zvine zvakasiyana siyana mapuroteni zvinoenderana kutevedzana zvachose kurondedzerwa DNA Morekuru mamiriro. mapuroteni izvi dzinoiswa kupinda 2 mumapoka: histones uye mapurotini negistony. In zvakaoma pamwe DNA renyukireya pakati pamakamuri, mapuroteni izvi inonzi chromatin.

Richirondedzera maumbirwo DNA, zvinofanira kucherechedzwa kuti chromatin rine mhando mashanu histones, zvachose zvakanaka kupomera chinopa simba chaizvo chisungo histones pamwe DNA. The zvakaoma pamusoro histones uye DNA molecules runotsanangurwa mugove zvakapoteredza ane 146 nucleotide mbiri, iri akaita, umo zvinoumba nucleosomes.

Vanobatanidzwa sechivako morekuru reDNA mapuroteni negistony zvinomiririra siyana mhando pamutemo mapuroteni, chokuita Kunyanya DNA sequences. Uyewo, DNA molecules nopindirana kuti maumbirwo makemikari kugovera biosynthesis.

Dzidza maumbirwo DNA uye RNA mukati hurongwa kuongorora inofanira chete kuva kunzwisisa, kuti, kana tichifunga sechivako DNA, zvakafanira kufunga marongerwo RNA.

mamiriro ayo chikuru, uyewo zvakaitika morekuru reDNA ane algorithm interlace ribonukleozidmonofosfatov, saka, kufungwa kuti, kusiyana DNA, marudzi ose RNA neketani imwe chete polynucleotide. Mune nemamiriro RNA Morekuru uye tambo dzayo kuroorwa vari kuumbwa, saka akadana "hairpin" - spiralized zvishwe zviri AU uye GC chawo uye muchidzikamiswa kuburikidza rehydrogen chokuedza.

Kazhinji, paavhareji kupfuura morekuru reDNA unotora 150 nucleotide mbiri millionov, uye kureba masendimita mana. Murabhoritari kuongorora mamorekuru akadaro zvikuru zvakavaomera yechidzidzo, nekuti kana ari yavaive pamusoro rinenge morekuru ruchigona kuva zvikuru ichiparara uye kuva duku zvikuru kukura. Kubvisa zvingasanakira ichi, vari kuongorora nzira pakati PCR - kuitisa polymerase cheni maitiro, umo iri zvokusarudza synthesizing nomumwe zvikamu morekuru reDNA, uye kuti govera kuti zvidzidzo zvakakodzera kuti ayo zvimedu.