DNA monomer. Chii monomers dzinoumba morekuru reDNA?

Nucleic acids, kunyanya DNA, zvinozivikanwa munyika unyanzvi. Izvi zvinotsanangurwa nokuti ndivo masero zvinhu chokuita kuchengetera uye kupararira magene mashoko ayo. DNA richakavazarukira muna 1868, F. Miescher ndiye morekuru pamwe simba acidic ehupfumi. Masayendisiti akaratidza kubva nuclei muropa masero - zvirwere masero. Mumakore akatevera 50 makore, kudzidza nucleic acids Zvaiitirwa neapo, sezvo masayendisiti akawanda vakatenda biochemists huru Organic zvinhu mutoro kusanganisira kuti nhaka unhu, mapurotini.

Sezvo decoding pakati sechivako DNA, kuitwa Watson uye Crick muna 1953, tanga kwakakomba kudzidza, zvakanzi vakawana kuti, deoxyribonucleic asidhi - iri polymer uye DNA monomers vari nucleotides. mhando dzavo uye ezvirevo zvichabviswa akadzidza nesu mubasa iri.

Nucleotides somunhu STRUCTURAL chairema magene mashoko

Chimwe chinokosha zvivako nyaya mhenyu - ndiko kuchengetedzwa uye kupararira mashoko marongerwo uye mashandiro anoita masero yose muviri. basa iri rinoitwa deoxyribonucleic asidhi uye DNA monomers - nucleotides vanomiririra kuti "Dzinovaka" umo rakasiyana magadzirirwo uye akavaka fuma nhodzera imwe mhando. Funga zviratidzo anotungamirirwa mhuka, nokusika supercoil nucleic acid.

Sei kuumba nucleotides

Kuti tipindure mubvunzo uyu, tinofanira zvimwe zivo kemisitiri ose Organic yeimwe. Zvikurukuru, tikayeuka kuti zvakasikwa pane boka senitrogen tubhokisi heterocyclic glycosides chokuita monosaccharides - pentoses (ribose kana deoxyribose). Ndivo vakadanwa nucleosides. Somuenzaniso, adenosine nezvimwe nucleosides varipo vari cytosol muchitokisi. Ivo vanoita pamwe mamorekuru of esterification pamwe orthophosphoric acid. Zvibereko izvi uye nucleotides vachadaro. Mumwe DNA monomer, uye pane mhando ina, ane zita Somuenzaniso, guanine, thymine uye cytosine nucleotide.

Purine DNA monomers

In nemakemikari omuviri kushandisa kupatsanura kuti wakapatsanura DNA monomers nokugadzirwa kwawo mumapoka maviri: somuenzaniso, purine ndiye adenine uye guanine nucleotides. Ivo ane dzavo sezvamunoita purine nomukaka - Organic fuma ane nzira C ₅ H ₄ N _4. Monomer DNA - guanine nucleotide, uyewo chine purine nitrogenous chawo kwakabatana kuti deoxyribose N-glycosidic chisungo uri betokonfiguratsii.

pyrimidine nucleotides

Nitrogenous zvingoro, akadana cytidine uye thymidine vari pyrimidine nomukaka zviri makemikari nyaya. fomura wayo C ₄ H ₄ N _2. Morekuru chinhu sandara-membered nhanhatu heterocycle ine mbiri Nitrogen maatomu. Zvinozivikanwa kuti panzvimbo thymine nucleotides vari mamorekuru pamusoro ribonucleic acid, akadai rRNA, tRNA, mRNA, yaiva uracil monomer. In nedanho transcription, panguva debiting mashoko kubva morekuru reDNA mu Gene mRNA thymine nucleotide kuchatsiviwa adenine, adenine nucleotide uye - kuti uracil muna mRNA nascent cheni. Ndizvo zvakanaka zviri zvinotevera kupinda: A - Y, T - A.

Mitemo Chargaff raMwari

Muzvirevo chikamu hatina kare zvishoma akabata pamusoro pemisimboti zvaidiwa monomers vari DNA ngetani uye kunzwisisa Gene mRNA. Mukurumbira zvipenyu E. Chargaff akasimbisa chaizvo yakasiyana pfuma pakati mamorekuru ose deoxyribonucleic acid, kureva kuti uwandu adenine nucleotides mairi nguva dzose akaenzana thymine, uye guanine - cytosine. The chikuru yokungotaura hwaro dzemitemo Chargaff sehofisi kudzidza Watson uye Crick, yokusarudza monomers dzinoumba morekuru reDNA, uye chii vane spatial sangano. Another muenzaniso outputted ne Chargaff akadana complementarity nheyo, inoratidza makemikari sungano pakati purine uye pyrimidine nezvigadziko dzavo kukwanisa kubata pakati pavo kuumbika rehydrogen zvisungo. Izvi zvinoreva kuti nokurongwa monomers zvose DNA tambo tisingatauri deterministic Saka, pakatarisana DNA wokutanga kunogona chete kuva T uye mumwe une mbiri rehydrogen zvisungo pakati pavo. cytosine chete inogona akaiswa pakatarisana guanine nucleotide. Muchiitiko chino, pakati nitrogenous nezvigadziko vanoumba zvitatu rehydrogen zvisungo.

Basa nucleotides ari majini Mubumbiro

Kuti dzika, maitiro kuitika ribosomes ari puroteni biosynthesis, pane ruzivo pamusoro rokushandura mashandiro ari amino iine acid Kuronga peptide kutevedzana kwezviitiko nucleotides vari mRNA kutevedzana kwezviitiko amino acids. Zvakaitika kuti vatatu pedyo monomer kutakura mashoko rimwe 20 zvinogoneka amino acids. Fani iyi inonzi majini remitemo. Pakugadzirisa matambudziko ezvinhu zvipenyu rinoshandiswa kuona zvose peptide amino iine acid sezvamunoita uye kujekesa mubvunzo: Nderipi rimwe morekuru reDNA monomers, mune mamwe mazwi, chii Kuronga runoenzanirana Gene. Somuenzaniso, zviri triplet (codon) AAA ari Gene inofananidzira iri amino iine acid phenylalanine ari puroteni Morekuru, uye masero Mubumbiro zvichaita kukodzera triplet UUU mu mRNA cheni.

Kusakarongeka pakati nucleotides panguva DNA kuberekana

Sepakutanga elucidated, ari STRUCTURAL vamapoka DNA monomers - nayo nucleotides. dzakananga urongwa hwavo mumatunhu ari template nokuda kwetunhu muitiro chikamu deoxyribonucleic asidhi Morekuru. Izvi zvinoitika muna S-padanho interphase masero. The nucleotide kutevedzana kwezviitiko itsva DNA molecules mu rwaamai kuenda ngetani kubudikidza enzayemu DNA polymerase pamwe nheyo complementarity (A - C, A - C). Kuberekana anoreva zvaiitwa chizvaro usage. Izvi zvinoreva kuti DNA monomers nokugadzirwa kwawo mukati mubereki cheni ndivo hwaro, kuti ndiye template kuti makopi aro chikamu.

Zvinogona kuchinja urongwa nucleotide

Zviya, ngativei vanoti deoxyribonucleic asidhi - iri kuchinja chaizvo nemamiriro muchitokisi musimboti. Pane zvichinzwisisika: mashoko majini anochengeterwa chromatin iri musimboti, anofanira akaramba uye kudzokororwa pasina kukanganiswa. Asi cellular genome iri kuramba "pasi pfuti" dzezvakatipoteredza zvinhu. Somuenzaniso, zvakadai zvechisimba makemikari yakaita doro, kushandisa zvinodhaka, radioactive nemwaranzi. Vose vanonzi mutagens, achifuridzirwa chipi DNA monomer anogona kushandura namakemikari kwavo mamiriro. kusarurama uku nemakemikari omuviri inonzi pfungwa mutation. The kakawanda panowanikwa munhu zvakakwana yakakwirira muchitokisi genome. Kunotouraya vari kugadziriswa zvakanaka-kutoitwa sero kugadzira hurongwa oparesheni, kusanganisira chine makemikari.

Vamwe vavo, zvakadai somunhu chakarambidzwa enzayemu, "kugurwa" ari hunenge nucleotides, polymerases kubvumira kwetunhu kwomuzvarirwo monomers ligase "crosslinked" akapora zvikamu Gene. Kana pamusoro mashandiro, vamwe chikonzero, sero asingashandi uye chakaremara DNA monomer unorambira ayo Morekuru, kuti mutation iri vakanongazve nokuda dzinotsanagura chizvaro usage uye phenotypically wakaratidzwa muchimiro mapuroteni pamwe zvakachinjwa ehupfumi, asingakwanisi kuita zvakafanira mabasa pakuona cellular muviri. Iyi haisi kunaka chinhu, nokuderedza sero chinhanho uye kuderedza nguva upenyu hwake.