Waxa ku jira sonkor DNA? saldhigyadii Chemical dhismeedka DNA ah

Sidee cajiib ah si ay u daawadaan sida la mid ah midba midka kale waa waalidiinta iyo carruurta. Or, on lid ku ah, kuwo ku kala duwan ka, iyo walaalihiis wiilal iyo gabdhoba, iyo hooyaday iyo aabe. Waa maxay sababta ay u dhacaan iyo maxay ku xiran tahay? Waa maxay qaababka ayaa ka mas'uul ah ilaalinta, xoojinta, kala iibsiga iyo muujinta calaamadaha ee farcankiis waalidkood?

doorka ay leeyihiinna acids ku nucleic in ay u sameeyaan koromosoomyada. In ay yihiin u taagoo in ku fuliyo hawlahan oo dhan geeddi socodka la xiriira hiddo iyo kala duwanaanshaha. xuquuqdeeda gaarka ah ee this iska leh taagoo DNA.

History of helitaanka acids nucleic

Muddo dheer oo ku saabsan taagoo, kuwaas oo lama yaqaan. Si kastaba ha ahaatee, in 1869, saynisyahan ka cilmi Miescher helay isku dar ah ee DNA iyo RNA, ka dibna wuxuu ahaa awoodaan in la dhiso in ay ka tirsan yihiin acids. Oo isna wuxuu sameeyey this by barashada unugyada dhiiga cad ee malax.

Tan iyo markaas bilaabay baadhitaan degdeg ah xeryahooda kuwan. saynisyahano badan ayaa isku dayay si loo ogaado Halabuurka kiimikada ee DNA iyo RNA ee. Si loo fahmo hiilinayn, qaabka iyo nooca doorka noolaha. kaalin weyn in this by dadka sida dhigay:

• A. N. Belozersky.
• Thomas Morgan.
• K. Bridges.
• A. Meller.
• G. de Vries.
• A. Sturtevant.
• G. A. Nadson.
• A. S. Serebrovsky.
• NP Dubinin.
• TS Filippov iyo kuwa kale.

In muddo ah ka 1900 in maanta uu caddeeyo nooca acids nucleic, saldhigyada kiimikada ah ee qaab-dhismeedka DNA, muuqaalada iyo muhiimadda ay leedahay noolaha. daahfurtay in lagu sameeyey, noo ogolaaday in la tixgeliyo this salaysan universal Britain oo dhan nolosha.

Research berrinkii genetics ayaa loo ogol yahay in la dhiso xiriirka ka dhexeeya DNA koromosoomyada hiddawadayaasha ah, si rayi code hidaha ee xayawaan oo badan oo ku nool. Waxa ay ahayd muhiim u ah fahamka cutubkan duur-joogta ah, hababka shaqo ee ay.

Sidoo kale, Halabuurka kiimikada ee koromosoom ah ayaa loo aqoonsaday. Waxa la ogaaday in ku saleysan - Britain a acid nucleic isagoo qaab gaar ah.

DNA: sifooyinka guud

Magaca oo buuxa qoraalka gaabiyay - deoxyribonucleic acid. Oo ay la socdaan acid RNA middani ay tiro ka mid ah nucleic. Helay magaceeda sababtoo ah DNA galo sonkorta. Its magaca - deoxyribose.

Walxaha kiimikada ee DNA iyo RNA aad ula mid yihiin, farqiga u sida wakhtiga ugu horayn in carbohydrate Britain ayaa la xirrira. In RNA waa ribose.

Guud ahaan, Britain ee acid deoxyribonucleic waa macromolecule a double ku xayiran adag isagoo miisaan kelli of Halabuurka weyn oo kala duwan. Sidaa darteed, inta badan oo ka mid ah xeryahooda ee image graphic uu leeyahay qaab laba qaybood, tallaabooyinka transverse isku daro - bonds.

In 1953, Chargaff iyo saaxiibtiis ay awoodaan in ay si buuxda u muujin qaab-dhismeedka gudaha iyo Halabuurka ee Britain, taas oo ahayd muhiimad weyn u dhan biology kelli iyo sayniska ee guud. Waxaa caddaatay in sonkorta shan-carbon waxaa ka mid ah saldhigyada DNA (pentose), purine iyo pyrimidine saldhigyadii iyo harta acid orthophosphoric.

Waxaa suurto gal ma aha oo kaliya in ay sii rayi qaabka aad u of xarunta, laakiin sidoo kale si ay u bartaan sifooyinka, jirka iyo kiimikada. Doorka noolaha iyo muhiimadda for shaqeeyo waxaa soo gaaray sida asaasiga ah, universal iyo gaar xoolahayaga oo kasta.

Halabuurka kiimikada

Haddii sifaha Halabuurka qaaradda iyo kelli hoose oo u taagoo acid nucleic, waxaa suurtagal ah in aqoonso dhawr nooc aasaasiga ah ee xeryahooda:

• pentose - deoxyribose (carbohydrate waa monosaccharide a);
• saldhigyadii organic - purine (adenayn iyo gu'anayn) pyrimidine (saytosayn iyo thaymiin);
• harta acid phosphoric la silsilado lacag la'aan ah.

Tani waxay, guud ahaan, dhammaan saldhigyada kiimikada ee qaab-dhismeedka DNA ah. Waxa kale oo ay tahay in isku-dar ah qaybaha oo dhan ma fududa, laakiin waa geedi socod adag oo u gaar ah. Sayidka, isku xiran deoxyribose, xataa salkeeda iyo intii ka hadhay acid imanba wada sameeyaan nucleotide ah. Waa mid ka mid ah isku xigxigta, nucleotide ah, oo uu yeeshay qaab-dhismeedka oo dhan Britain oo dhan.

Gaar ah waa isku xigxiga ay ku salka organic laga dhisi doonaa mid kale oo ka dambeeya iyo in la xiriirta silsilad ku xiga. xigxiga nucleotide waxaa la dhisay sida ay mabaadi'da gaar ah, oo madax ka mid ah taas oo ah complementarity (purine waafaqsan adag iyo qaybaha pyrimidine). Tani waxay u ogolaaneysaa qof kasta aadanaha u leedahay in ay code genetic, gaar, dhalin iyo qoto-gaar ah.

Phenotype lagu muujiyey qaab isku xigta ka mid ah sifooyinka aad u kala duwan, in aanay jirin laba qof oo isku mid ah (marka laga reebo mataanaha isku midka ah), muuqaalada garan muuqaalka.

Dhismaha DNA waxaa ka mid ah sonkorta kasta?

Ku saleysan kasta oo arrinta organic - a atamka silsilad carbon. Britain DNA ma aha marka laga reebo ah. Ka dib oo dhan ee DNA galo sonkorta, kuwaas oo, waxay ka kooban tahay isku xigxiga oo ka mid ah shantii atamka carbon, marka la isku daro in qaab xilliile ah. Britain ayaa waxa ay sidoo kale kala gooyey by buundada oxygen ah gudahood wareegga guud.

Walxaha kiimikada ee sonkor ah waxaa lagu qeexay by formula taaban soo socda: C ₅ H ₁₀ O _4. Britain Tani - aldopentoza oo ka kooban shan atamka carbon, qaloocdo galay loop a. Intaa waxaa dheer, mid ka mid ah atamka ee silsiladda halkii group hydroxyl ku jira oo keliya hydrogen, sidaas darteed waxaa jiray horgale sida "deoxy" ee horyaalka sonkorta, i.e., oo aan ogsijiin.

Walxaha kiimikada oo sonkor ah la helay iyo bartay Fibusom Lieven, kuwaas oo furay dhismaha oo dhan iyo nooca kiimikada ee xarunta 1929.

Base in Britain ay

saldhigyadii Organic yihiin qayb ka mid ah nucleic DNA ee acid loo qaybin karaa laba kooxood oo ugu waaweyn.

1. Purine - dhismeedka kakan sameeyay laba ka mid ah wareegga carbon ah - a shan membered iyo lix-membered. Kuwaas waxaa ka mid adenayn iyo gu'anayn, oo waa kaabaha saldhig pyrimidine ka kooban deoxyribonucleic acid ah.
2. Pyrimidine - lix membered siddo carbon. Tan waxaa ka mid thaymiin iyo saytosayn.

Sidaas darteed, waxa ay u muuqataa in qayb ka mid ah sonkorta DNA iyo saldhigga ah oo ku xiran in midba midka kale iyo ku xiran by links la xagjirka ah ee phosphoric acid. All wada ay muuqato nucleotide. Qaab-dhismeedka guud ee nucleotides Britain DNA double-ku xayiran ku murmeen dhexdooda ku xidhaan sida ay caadiga ah ee complementarity: saldhig adenayn u dhiganta thaymiin, gu'anayn iyo - saytosayn.

Noocyada bonds dhexeeya qayb ka ah

Noocyada ugu muhiimsan ee xidhiidhada u dhexeeya dhismayaasha DNA component sida soo socota:

• hydrogen,
• covalent horjeeda;
• Ciidamada intermolecular ee soo jiidashada,
• Vahan der Waals dhexgalka.

Tani waxay aad u ogolaanaya in ay double-ku xayiran qaab-dhismeedka jira saddex conformations:

• hoose - xigyada toosan ee nucleotides;
• sare - kasta daah helically qaloocdo iyo laba soo socota in kasta oo kale;
• jaamacadda - globule conformational adag si adag u Britain ayaa ku helical.

Sayidka xaqiiqda ah in qayb ka mid ah DNA soo gashay harta sonkorta, salka, iyo acid waa ku salaysan qaab-dhismeedkooda iyo ciidda loogu talagalay hirgelinta tiro ka mid ah isdhexgalka iyo formation of bonds kiimikada.

qiimaha DNA for noolaha

Waxaa jira dhowr qodob oo aad u muhiim ah:

1. Taagoo tixgeliyo acids ku jira Halabuurka kiimikada ee koromosoom in loo ogaado aqoonsiga noolaha oo dhan ka.
2. DNA - saleysan Avv silsilado polypeptide adag ka masuul ah koodh iyo gudbinta sifooyin kala dhaxlo.
3. acid Deoxyribonucleic - saldhig waayo, qoraal, i.e. Avv RNA hoose, protein danbe.

Hababka noocaas ahi ka dhacaan oo dhan noolaha. Tani waxay u ogolaaneysaa dhismeedka this yiraahdo qaybta caalamiga ah ee wax nool oo dhan.

adkeyneyna taagoo

Marxaladani waxay ka dhigan tahay labanlaabka ah ee Britain ayaa DNA, degna dhaca la kharash ah ee tamarta noolaha. component ugu weyn ee ay dhacdo in this - DNA polymerase, catalyzing enzyme ah iyo xakamaynta Avv oo dhan.

dhibic taranka waa in mid kasta oo ka mid ah qaybood ee Britain ayaa ugu kala qaybsameen oo ay laba-laab ay isku xigxiga toosan. Geedi socodka keentay soo saartaa laba taagoo DNA cusub oo kasta taas oo ka kooban hal silsilad polypeptide jir ah, iyo labaad oo gebi cusub, dhisey si waafaqsan mabda'a complementarity.

Qiimaha Geeddi-socodka - si ay u bixiyaan Farac ka mid ah macluumaad hidde ee guud ahaanteed.