Yintoni idityanisiwe iswekile DNA? iziseko chemical lobume DNA

Indlela emangalisayo ukubukela indlela efanayo omnye komnye abazali nabantwana. Okanye, phezu koko, eyahlukileyo kakhulu, kunye nabazalwana noodade, kunye nomama notata. Kutheni oko kwenzeka kwaye kusiya ntoni? Zeziphi izigqeba banoxanduva ulondolozo, ukudityaniswa, ukhutshelo yokubonisa iimpawu kwi inzala kubazali babo?

Loo ndima fanele ukuba asidi acid ukuba zibe zofuzo. Ukuba iimolekyuli ukuba enze imisebenzi zonke iinkqubo ezinxulumene ufuzo kunye nomahluko. kungumsebenzi olulodwa oku okuya iimolekyuli DNA.

Imbali ngexesha lokufunyanwa nucleic

Kangangexesha elide malunga ezi molekyuli ayaziwa. Noko ke, ngo-1869, enye ingcali yenzululwazi ukusuka kuphando Miescher wafumana umxube DNA kunye RNA, yaye emva koko waba nako ukumisela ukuba bengabakho asidi. Wakwenza oku ngokufunda iiseli ezimhlophe zegazi ubomvu.

Ukususela ngoko waqalisa ukufunda nzulu ezi zinto. Izazinzulu abaninzi baye bazama ukumisela ubume eekhemikhali DNA kunye RNA. Ukuze siqonde ubuntu babo, isakhiwo nohlobo indima eziphilayo. Igalelo elikhulu oku kwenziwa ngabantu ezifana:

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

Kweli thuba ukususela 1900 ukuya namhlanje iye icaciswe uhlobo nucleic, iziseko imichiza kwesakhiwo DNA, iimpawu zayo kunye nokubaluleka eziphilayo. ezifunyaniswe lwenziwe, ngokusivumela ukuba siqwalasele le isiseko molecule sifikelele bonke ubomi.

Uphando entsimini zofuzo kuvunyelwa ukuseka ubudlelwane phakathi DNA kunye zofuzo genome, United States ikhowudi yezofuzo yezidalwa ezininzi eziphilayo. Kubalulekile ukuba ukuqonda yeyunithi zasendle, iindlela zayo zokusebenza.

Kwakhona, ubume eekhemikhali chromosome sele zichongiwe. Kuye kwafunyaniswa ukuba isiseko - esidi molecule nucleic ukuba isakhiwo ethile.

DNA: iimpawu ngokubanzi

Elipheleleyo Igama abbreviation umbhalo - deoxyribonucleic acid. Kunye nale acid RNA libekisa kwinani nucleic. Wafumana igama layo ngenxa DNA engena iswekile. igama layo - deoxyribose.

Le khemikhali Ukubunjwa DNA kunye RNA ziyafana kakhulu, umahluko njengoko kwexesha kakhulu carbohydrate bokwakha molecule. Xa RNA ribose.

Ngokubanzi, esiti molecule ideoxyribonucleic i macromolecule kabini ndixakene complex ukuba ubunzima beemolekyuli kombhalo kakhulu kwaye zahlukene. Ngoko ke, uninzi iikhompawundi yomfanekiso graphic na uhlobo imisonto emibini, amanyathelo ezinqamlezayo zihlangene - izitropu.

Ngowe-1953, Chargaff kunye noogxa bakhe ukwazile ukutyhila ngokupheleleyo isakhiwo lwangaphakathi kunye nokwakhiwa kwemolekyuli, nto leyo ibaluleke gqitha lonke ezinto eziphilayo nenzululwazi ngokubanzi. Kuye kwacaca ukuba xa iswekile carbon ezintlanu-kuquka iziseko DNA (pentose), purine kunye pyrimidine bajula iintsalela acid orthophosphoric.

Kuyenzeka nje kuphela ukuwuqonda ngakumbi kanye isakhiwo compound, kodwa ukufunda iimpawu, ngokwasemzimbeni kunye imichiza. Indima eziphilayo nokubaluleka kuba eziphilayo ethathwa njengendlela esisiseko, jikelele kunye ezithile ubutyebi nganye.

chemical ukubunjwa

Ukuba elichaza yangaphakathi kuqamba atom ezinto ezi molekyuli acid nangenucleic, kunokwenzeka ukuba ukuchonga iintlobo ezisisiseko iikhompawundi:

• pentose - deoxyribose (carbohydrate i monosaccharide);
• iziseko organic - purine (adenine kunye guanine) pyrimidine (cytosine kunye thymine);
• iintsalela acid phosphoric ngemixokelelwane simahla.

Oku, ngokubanzi, zonke iziseko eekhemikhali ubume DNA. Enye into kukuba idibanise zonke ezi macandelo akuyonto ilula, kodwa yinkqubo entsonkothileyo ezizodwa. Ngenxa yoko, ezihlangene deoxyribose, isiseko kunye nentsalela acid nezingaphiliyo ndawonye bakha nucleotide. Kuyinto enye ulandelelwano nucleotide, kwaye kuphuhlisa isakhiwo yonke kwemolekyuli xa iyonke.

Eyahlukileyo indlela ezilandelelana ngayo isiseko ephilayo iya kuba omnye emva komnye, ngokunxulumene kwitsheyini ezikufutshane. Ulandelelwano nucleotide yakhiwa ngokwemigaqo ethile, omkhulu phakathi apho complementarity (sivumelane purine engqongqo kunye namacandelo pyrimidine). Oku kukuvumela ukuba wonke umntu ukuba ikhowudi yayo yemfuza, a unique, isegazini yaye zinzulu-ngqo.

Phenotype esibonakaliswa ngohlobo zoludwe lweempawu ezahlukeneyo ngokupheleleyo, ukuba akukho bantu babini twatse (ngaphandle namawele afanayo), iimpawu olwahlula imbonakalo.

Ubume be-DNA kuquka na iswekile?

Isiseko nawuphi na umcimbi eziphilayo - a athom carbon chain. Kwemolekyuli DNA akuyona umnyinyiva. Emva kokuba yonke iDNA ongena iswekile, oko kukuthi, loo nto iquka kulandelelwano athom ezintlanu carbon, ezidityanisiweyo kwisakhiwo elibujikele. Le molecule efanayo lungqubano lomncedis ka X. ibhulorho ioksijini ngaphakathi kumjikelo lulonke.

Ukubunjwa eekhemikhali iswekile kubonakaliswa indlela reseach zilandelayo: C ₅ H ₁₀ O _4. Le molecule - aldopentoza eliquka athom ezintlanu carbon, aphothwe ibe loop. Ukongeza, omnye atom ezikwi endaweni iqela hydroxyl i iqulethe kuphela hydrogen, ngoko kwakukho isimaphambili ezifana "deoxy" kwi isihloko iswekile, ngamanye amazwi, ingekho i-oksijini.

Le khemikhali Ukwakhiwa iswekile uyaziwa kwaye wafunda Fibusom Lieven, wawavulayo lonke kwisakhiwo nakuhlobo lwemichiza compound ngo-1929.

Base kwi molecule

iziseko Organic ukuba yinxalenye ye-DNA nucleic acid zingahlulwa zibe ngamaqela amabini eziphambili.

1. Purine - izakhiwo ezintsonkothileyo ezenziwa ezimbini kumjikelo carbon - eyayintsuku-membered ezintandathu-membered. Ezi ziquka adenine kunye guanine, ezo iyavumelana ukuba isiseko pyrimidine eyakhiwa deoxyribonucleic acid.
2. Pyrimidine - emithandathu-membered amakhonkco carbon. Oku kuquka thymine kunye cytosine.

Ngoko ke, kubonakala ukuba yinxalenye sugar DNA kunye nesiseko enxulumene omnye komnye yaye eziqhagamshelene ukunxibelelana ngokugqibeleleyo of phosphoric acid. Bonke kunye uphendulela nucleotide. Isakhiwo jikelele nucleotides yomoya DNA kabini-ndixakene Ububophe phakathi kwawo ngokomgaqo othile of complementarity: kwisiseko adenine ingqamana thymine, guanine kunye - cytosine.

Iintlobo isibopho phakathi kweengqakumbana

Eyona eziphambili ze ubudlelwane phakathi izakhiwo DNA candelo ngolu hlobo lulandelayo:

• hydrogen;
• covalent polar;
• amandla aphakathi yomtsalane;
• UVahan der Waals intsebenziswano.

kuvumela oku ukuba kabini-balahleke isakhiwo kweerekhodi conformations ezintathu:

• samabanga - ulandelelwano linear of nucleotides;
• ngalinye ngokuluhlaza helically ejijekileyo kunye ezimbini ecaleni kwenye - ezizisekondari;
• tertiary - globule entsonkothileyo conformational ngamandla molecule helical.

Ngoko ke into yokuba inxalenye DNA kuya iintsalela iswekile, angamatshijolo, kwaye asidi sisiseko isakhiwo kunye nomhlaba lokuphunyezwa inani leendibano kunye ukuyilwa iibhondi imichiza.

ixabiso DNA ye eziphilayo

Kukho iingongoma ezibalulekileyo kakhulu ezininzi:

1. Iimolekyuli ingqalelo asidi zibandakanywa umchiza ukwakhiwa zofuzo ezibonakalisa ngubani zonke izinto eziphilayo.
2. DNA - isiseko Yindibanisela xo polypeptide entsonkothileyo onoxanduva ukhowudo kunye nokusasazwa imikhwa zamafa.
3. Deoxyribonucleic acid - isiseko umbhalo, ngamanye zamabanga kuyondelelaniswe RNA, iiproteins kamva.

iinkqubo ezinjalo kwenzeka kuzo zonke izinto. Oku kukuvumela le ebizwa unit jikelele zonke izinto eziphilayo.

ukulingisa molecule

Le nkqubo imele kabini kwemolekyuli DNA, ezenzeka ngokuzenzekelayo kunye nenkcitho amandla eziphilayo. Eyona ingxenye main kulo mzekelo - DNA polymerase, i catalyzing enzyme nokulawula yonke ehlaziya.

Ukuphindaphindeka Ingongoma kukuba ngalunye kwiindawana kwemolekyuli esahluleleneyo kwaye iye kabini ngokulandelelana kwayo yomgama. Inkqubo ngenxa ivelisa iimolekyuli ezimbini ezintsha DNA ye nganye equlethe omnye ikhonkco polypeptide ubudala, kwaye eyesibini entsha ngokupheleleyo, lwakhiwe ngokumalunga umgaqo complementarity.

Inkqubo Value - ukubonelela siyinzala imizila yemfuza ngokupheleleyo.