Gịnị bụ reduplication nke DNA? The usoro nke DNA replication

The DNA molekul - emi odude ke chromosome Ọdịdị. Otu chromosome nwere otu molekul esịnede abụọ uzo. Reduplication nke DNA - bụ nyefe nke ozi mgbe onwe onye na-amụba nke eri site na otu molekul ọzọ. Ọ bụ pụta ụwa ma DNA na RNA. Isiokwu a kwuru banyere ndị DNA imepụtaghachi.

General ọmụma na ụdị nke DNA njikọ

Ọ maara na a kpara akpa yarn na molekul. Otú ọ dị, mgbe usoro nke DNA replication amalite, ha dispiralized, mgbe ahụ emee ewepụta, na na onye ọ bụla ọhụrụ oyiri na-synthesized. N'elu ẹkụre e nwere abụọ kpamkpam yiri ụmụ irighiri ihe, ọ bụla nke na e nwere a nne na nna na a na nwa na eri. Nke a njikọ a na-akpọ ọkara mgbanwe. DNA ụmụ irighiri na-akpali, mgbe fọdụrụ na a otu centromere, na n'ikpeazụ diverge naanị mgbe a centromere nkewa usoro amalite.

The ọzọ ụdị a na-akpọ reparative njikọ. Ọ, n'adịghị gara aga otu, na-adịghị metụtara ọ bụla cell ogbo, ma na-amalite na ihe omume nke DNA mebiri. Ọ bụrụ na ha na-oke obosara-sitere na uwa, na cell-emecha-anwụ anwụ. Otú ọ dị, ọ bụrụ na ndị mebiri bụ obodo, mgbe ahụ, ị nwere ike iweghachi ha. Dabere na nsogbu ga-eweghachi ma ọ bụ ikewapụ uzo ihe abua nke DNA ozugbo. Nke a, dị ka ọ na-akpọ, unscheduled njikọ dịghị ewe ogologo oge na-adịghị achọ ka a ezigbo ike.
Ma mgbe e nwere a reduplication nke DNA, mgbe ahụ nọrọ ọtụtụ ume, na ihe onwunwe, agbatị na ogologo nke ya nche.
Reduplication ekewa atọ oge:

• nnabata;
• elongation;
• nchupu.

Ka anyị tụlee na nsoro nke DNA replication.

nnabata

Na mmadụ DNA - a ole na ole ọtụtụ iri nde ndị isi ụzọ abụọ (ụmụ anụmanụ ha igu nanị otu narị na iteghete). DNA reduplication amalite ọtụtụ ebe ndị yinye maka ndị na-esonụ mere. Gburugburu otu oge na RNA transcription emee, ma na njikọ nke DNA na-kwụsịtụrụ na ụfọdụ nke ahọrọ ebe. Ya mere, ndị dị otú ahụ a usoro tupu a zuru ezu ego nke umi accumulates na cytoplasm nke mkpụrụ ndụ iji kwado site n'usoro okwu na cellular ọrụ na-adịghị a gbajiri agbaji. N'ihi nke a, usoro ga-ebe dị ka ngwa ngwa o kwere omume. Ohuru n'oge a rụrụ, na transcription na-adịghị duziri. Studies gosiri na DNA reduplication emee otu na ọtụtụ puku ihe - obere ebe a kpọmkwem nucleotide usoro. Ha na-esonyere pụrụ iche initiator edozi, nke n'aka nke na-esonyere ndị ọzọ enzymes nke DNA replication.

The DNA ibe akwụkwọ nke na-synthesized a na-akpọ a replicon. Ọ na-amalite site ná mmalite na-agwụ mgbe enzyme rụchara replication. Replicon bụ kwurula, na-enye dum usoro nke ya software.
The usoro nwere ike na-amalite site na niile ihe otu mgbe, ebe ọ na-amalite ya na mbụ, ebe - e mesịrị; Ọ nwere ike na-ebe ihe na otu ma ọ bụ abụọ na-abụghị ntụziaka. The ihe na-ewere ọnọdụ na-esonụ iji mgbe oyiyi:

• replication ndụdụ;
• RNA primer.

replication ndụdụ

Nke a na akụkụ ọnọde a usoro ebe na ná mgbagwoju yarns na-synthesized DNA deoxyribonucleic filaments. Plọg otú etolite a na-akpọ anya nke replication. The usoro a kpọkwasịwo a ọnụ ọgụgụ nke omume:

• nyak si njikọ na histones na a nucleosome - enzymes dị ka a DNA replication methylation, acetylation, na phosphorylation emepụta chemical Jeremaya mere na-ebute na-edozi ida ha mma ụgwọ na mmemmem tọhapụsịrị ha;
• despiralization - bụ unwinding, nke dị mkpa maka ahụ n'ihu ntọhapụ nke eri;
• agbaji hydrogen nkekọ dị n'etiti DNA uzo;
• ha divergence na dị iche iche n'akụkụ abụọ nke molekul;
• fixation aa iji SSB edozi.

RNA primer

Njikọ eburu ihe enzyme a na-akpọ DNA polymerase. Otú ọ dị, iji malite ya ọ pughi, otú ndị ọzọ enzymes - na RNA polymerase, nke a na-akpọ RNA primers. Ha na-synthesized ke ukem nke na-adị deoxyribonucleic na ụkpụrụ nke complementarity. N'ihi ya, ihe mmalite nke RNA njikọ nke nsọtụ abụọ, abụọ primers na wezugaghi tisasịrị DNA uzo.

elongation

Oge a na-amalite site nucleotide mgbakwunye na 3 'ọgwụgwụ nke RNA-primer, nke na-eburu ekwuola DNA polymerase. Ọ attaches ka mbụ nke abụọ, nke atọ nucleotide, na na. New eri isi jikọọ na nne na nna yinye site hydrogen agbụ. Ọ na-kweere na njikọ nke yarn bụ na 5 '- 3'.
Ebe ya emee ke n'akụkụ nke replication ndụdụ, na njikọ na-ewe ebe nọgidere na n'otu oge ahụ dịkwuo ogologo. Ya mere, a na eri na-akpọ ndị na-eduga ma ọ bụ na-eduga. Ọ RNA primer na-agaghịkwa kpụrụ.

Otú ọ dị, na-abụghị Strand nke nne na nna DNA nucleotides-anọgide na-esonyere ndị na RNA primer, na deoxyribonucleic yinye na-synthesized na-abụghị uzo si replication ndụdụ. Na nke a, a na-akpọ na-egbu oge ma ọ bụ lagging.

Na lagging Strand njikọ emee adakpọọla, nke otu ọgwụgwụ òkè nke njikọ na-amalite mgbe ọnọdụ ọzọ nso iji na otu RNA primer. N'ihi ya, e nwere ihe abụọ na-egbu oge yinye ibe akwụkwọ na-sonyeere DNA na RNA. Ha na-akpọ Okazaki iberibe.

Mgbe ahụ ihe niile na-ugboro ugboro. Mgbe ahụ spliced ọzọ uzo nke helix, hydrogen wupu nkwurịta okwu eri n'akụkụ, na-eduga yinye lengthened na lagging synthesized esonụ papaịrọs RNA primer, whereupon - Okazaki itisa. Mgbe nke ahụ gasịrị, na a na-egbu oge-Strand RNA primers na-ebibi na DNA iberibe na-sonyeere n'ime otu. Ya mere nke a circuit ewe ebe n'otu oge:

• guzobe ọhụrụ RNA primer;
• njikọ nke Okazaki rifọrọ;
• mbibi nke RNA primers;
• jikọghachiri n'ime otu circuit.

nchupu

The usoro na-aga n'ihu dị ka ogologo dị ka abụọ ndị ahụ replication ndụdụ, ma ọ bụ otu onye n'ime ha ga-abịa na njedebe nke molekul. Mgbe a gbasara, ndụdụ DNA nwa uzo na-esonyere ndị enzyme. Na ikpe, ma ọ bụrụ na na nkwụnye na-akpali kwupụta ọgwụgwụ nke molekul, DNA reduplication njedebe iji pụrụ iche enzymes.

mgbazi

Na usoro a, ọrụ dị mkpa na e kenyere ya akara (ma ọ bụ mgbazi) nke replication. Ebe njikọ enweta niile anọ na ụdị nke nucleotides, na nyocha site DNA polymerase pairing ahọrọ ndị na-mkpa.

The chọrọ nucleotide na-enwe ike na-etolite hydrogen nkekọ nakwa dị ka yiri nucleotide na template DNA Strand. Ọzọkwa, n'etiti sugar-phosphate idé ga nwere ihe ụfọdụ na mgbe nile na-anya kwekọrọ atọ yiri mgbaaka na abụọ bases. Ọ bụrụ na ndị nucleotide adịghị izute ndị a chọrọ, njikọ ahụ ga-adịghị eme.
Control a rụrụ n'ihu ya na webata circuit na n'iru mbịne na ụdi nucleotide. Mgbe ahụ, na njikọ ahụ idé saharofosfata.

mutational mgbanwe

The usoro nke DNA replication, n'agbanyeghị elu pasent nke ziri ezi bụ mgbe niile na-enwe nsogbu ndị filaments, nke na-akpọ ukwuu n'ime "site n'usoro mmụba." About a puku isi ụzọ abụọ, e nwere otu onye ndudue na konvariantnaya akpọ reduplication.

Ọ na-eme dị iche iche ihe. Ka ihe atụ, na elu ma ọ bụ oke ala kasịnụ nke nucleotides deamination nke-agakọta, ọnụnọ nke mutagens na njikọ nke abụọ. Mgbe ụfọdụ, njehie nwere ike idozi site mmezi Filiks ndị ọzọ mgbazi na-aghọ-agaghị ekwe omume.

Ọ bụrụ na ndị mebiri na-emetụta ndị na-ehi ụra ohere, ihe njehie ga-enweghị akwa ya pụta mgbe e DNA imepụtaghachi. Nucleotide usoro nke a site n'usoro nwere ike ime na mating njehie. Mgbe ahụ, ọ bụ bụghị ikpe, na a na-ezighị ezi pụrụ ịbụ ka ọnwụ nke cell, na ọnwụ nke dum organism. Ọ kwesịkwara iburu n'uche na site n'usoro mmụba na-dabere na mutational mgbanwe, nke na-eme ka mkpụrụ ndụ ihe nketa na ọdọ mmiri nke plasticity.

methylation

Mgbe oge nke njikọ, ma ọ bụ ozugbo na ọ na-adị methylation ígwè. Ọ na-kweere na nke a dị mkpa maka a onye na-etolite chromosomes ma mezie site n'usoro transcription. Na usoro a bacteria nke DNA na-eje ozi ya nchedo ịcha enzymes.