The degeneracy pa malamulo majini: ndizosowa

Ndondomekozi majini chimaonetsera codons, dongosolo la kabisidwe zokhudza kapangidwe ka mapuloteni, chibadidwe zamoyo zonse za padziko lapansi. Decryption kutenga zaka, koma kuti aliko, sayansi anamvetsa pafupifupi zaka. Ntchito zake zosiyanasiyana, kulunjika, unidirectional, makamaka degeneracy pa malamulo majini ndi tanthauzo kwachilengedwenso.

History of atulukira

Vuto la kabisidwe mudziwe majini wakhala zikuluzikulu zamoyo. Ndi kapangidwe masanjidwewo pa malamulo chibadwa, sayansi patsogolo m'malo pang'onopang'ono. Popeza anapeza J. Watson ndipo Crick mu 1953. awiri helix Kapangidwe ka DNA analowa gawo la kuthetsa kachidindo kapangidwe lokha, lomwe analichita chikhulupiriro mu ulemerero wa chilengedwe. Kapangidwe liniya mapulotini DNA ya kapangidwe chomwecho anasonyeza pamaso pa malamulo majini, ndi makalata pakati pa malemba awiri, koma analembedwa ndi alifabeti osiyana. Ndipo ngati zilembo mapulotini wakhala kudziwika, zipsera DNA anali phunziro la a zamoyo, sayansi ndi masamu.

Osada kufotokoza njira zonse mu njira ya chosamvetsetseka izi. Direct kuyesera, anali ndi kutsimikizira kuti pakati codons DNA ndi amino zidulo mapuloteni pali bwino ndiponso zogwirizana ankalemekeza unachitikira mu 1964 Charles Janowski ndi S. Brenner. A zina - pa decoding za malamulo opanga khalidwe m'galasi (mu m'galasi) pogwiritsa ntchito njira ya kaphatikizidwe mapuloteni mu nyumba selo ufulu.

Kwathunthu decrypted malamulo E. coli anali promulgated mu 1966, akatswiri pa nkhani yosiyirana pa Cold Spring Harbor (USA). Ndiye ine anatsegula redundancy (degeneracy) ya malamulo chibadwa. Kodi izi zikutanthauza, izo anafotokoza ndithu chabe.

decoding akupitiriza

Kupeza chinawathandiza kumvetsa n'chakuti deta cholowa malamulo wakhala mmodzi wa zinthu zofunika kwambiri Mu zaka zapitazo. Lero, sayansi akupitiriza kufufuza mwakuya ndi njira ya dongosolo maselo kabisidwe ndi mbali zake ndi overabundance zizindikiro, zimene zili katundu wa degeneracy pa malamulo chibadwa. Kafukufuku osiyana makampani - chiyambi ndi zamoyo wa cholowa dongosolo chuma 'kala' ikusonyeza. Umboni yolumikiza polynucleotides (DNA) ndi polypeptides (mapuloteni) linapereka kuti pakhale zamoyo. Ndipo kuti nawonso, umisiri, bioengineering, kufufuza mu kuswana ndi mbewu kukula.

Mbalume ndi malamulo

Home chiphunzitso cha zamoyo - mfundo ndi inasamutsidwa kuchoka DNA Mtumiki RNA, kenako naye mapuloteni lapansi. Zosiyana kwa HIV ndi zotheka kwa RNA kuti DNA ndi RNA pa RNA ena.

Koma masanjidwewo kapena maziko a DNA nthawi chikhalire. Ndi zina mbali zonse zoyambirira za kusintha zambiri - kusonyeza chikhalidwe cha kulanda masanjidwewo lapansi. Ndicho, ndi kuchita kufala kwa kaphatikizidwe mamolekyulu ena masanjidwewo, limene lidzakhala kubalana wa kapangidwe ka mfundo chibadwa.

kachidindo majini

Mzere wolemba pulogalamu Kapangidwe ka zedi mwa wowonjezera codons (atatu) nucleotides, amene yekha 4 (adein, guanine, cytosine, thymine (uracil)), zomwe zokha kumabweretsa mapangidwe unyolo zina nucleotides. The nambalayi wa nucleotides ndi mankhwala mapolojekiti - ichi ndi chikhalidwe chachikulu kaphatikizidwe amenewa. Koma mapangidwe mapuloteni molekyulu khalidwe zofanana kuchuluka ndi khalidwe la monomers si (DNA nucleotides - mapuloteni kwa amino zidulo). Izi ndi za chilengedwe cholowa kachidindo - dongosolo kujambula mu ndondomeko ya nucleotides (codons) ndi kwa amino asidi ndondomeko ya mapuloteni ndi.

Majini kachidindo ali katundu zingapo:

• Triplet.
• Wapadera.
• Lathu.
• Disjointness.
• Redundancy (degeneracy) ya malamulo chibadwa.
• Zosiyanasiyana.

Apa ikulongosola mwachidule, moganizira kufunika kwachilengedwenso.

Triplet, kupitiriza ndi kupezeka stoplights

Aliyense wa 61 amino zidulo lolingana ndi zamalankhulidwe T (triplet) nucleotides. Atatu atatu Musatenge zokhudza asidi kwa amino ndipo ali oyima codons. Aliyense nyukiliotayidi mu unyolo ndi membala wa triplet, ndipo kulibe palokha. Kumapeto ndi chiyambi cha unyolo nucleotides lolingana mapuloteni limodzi, ndi codons amasiya. Iwo amayamba kapena amasiya wailesi (kaphatikizidwe wa mapuloteni molekyulu).

Kulunjika, ndipo limodzi pointedness disjointness

Aliyense codon (triplet) encodes chimodzi chokha kwa amino acid. Aliyense triplet ndi odzilamulira okha ndipo alibe alipo pafupi. nyukiliotayidi wina amadziwika ndi triplet chimodzi chokha mu unyolo. Mapuloteni kaphatikizidwe nthawi zonse mu njira imodzi yokha, kuti ukulamulidwa amasiya codons.

The redundancy pa malamulo majini

Aliyense triplet wa nucleotides encodes kwa amino asidi wina. A okwana nucleotides 64, 61 iwo - ndiyotengera kwa amino asidi (tanthauzo codon), ndi atatu - tanthauzo, mwachitsanzo kwa amino asidi si encode (kusiya codons). The redundancy (degeneracy) ya malamulo kumtundu kuti oloŵa m'malo mukhoza kupanga chilichonse triplet - kwakukulu (zikubweretsa kwa amino asidi m'malo) ndi ndiwofatsa (amino zidulo sasintha kalasi). N'zosavuta kuwerengetsa kuti ngati triplet angathe kuchitidwa 9 oloŵa m'malo (1, 2 ndi 3 udindo), aliyense nyukiliotayidi akhoza m'malo ndi 4 - 1 = 3 chimake ena, chiwerengero cha zotheka oloŵa m'malo nyukiliotayidi adzakhala 61 mpaka 9 = 549.

The degeneracy pa malamulo majini zikusonyezedwa chakuti options 549 - ndi zambiri kuposa koyenera kuti mudziwe zakodirovki 21 kwa amino zidulo. Pankhaniyi mungachite m'malo 549 23 kutsogolera mapangidwe kuletsa codon, 134 + 230 M'MALO - ndi ndiwofatsa oloŵa m'malo, ndi 162 - kwakukulu.

Kulamulira degeneracy ndi kuchotserapo

Ngati codons awiri ndi ziwiri zofanana woyamba nyukiliotayidi, ndi nucleotides atsala anapatsidwa kalasi (purine kapena pyrimidine), mfundo akupereka chomwecho kwa amino acid. Izi kawirikawiri degeneracy kapena redundancy pa malamulo chibadwa. kupatulapo awiri - AUA ndi UGA - woyamba encodes methionine, ngakhale anayenera isoleucine, ndipo chachiwiri - kuletsa codon, koma anayenera encode tryptophan.

Kutanthauza degeneracy ndiponso ntchito zake zosiyanasiyana

Izi zimatha awiri pa malamulo majini ndi apamwamba mtengo kwachilengedwenso. katundu onse amene ali pamwambawa ndi khalidwe mfundo chibadwa a mitundu yonse zamoyo padziko lathuli.

The degeneracy pa malamulo majini ali kufunika dziphunzitsiranso, ngati mwendo mobwerezabwereza limodzi kachidindo kwa amino acid. Komanso, izi zikutanthauza kuchepetsa kwambiri (alibe) wa nyukiliotayidi wachitatu codon a. Chotero chimake ndi minimizes ndi zotupa mutational mu DNA, zomwe zikuphatikizapo kuswa mu dongosolo mapuloteni. Iyi ndi njira kuteteza zamoyo za padziko lapansi.