Kapangidwe ka DNA imakhala ... mipweya ya DNA

Anthu ambiri nthawi ndinadabwa chifukwa zizindikiro zina zilipo makolo kupereka mwana (mwachitsanzo, diso mtundu, tsitsi, mawonekedwe nkhope, ndi ena). Science zatsimikiziridwa kuti kusintha khalidwe zimadalira zinthu chibadwa, kapena DNA.

DNA ndi chiyani?

Panopa pansi chidulo deoxyribonucleic kumvetsetsa zovuta pawiri kuti ndi udindo kufala kwa makhalidwe cholowa. molekyulu opezeka yonse yochepetsetsa ya thupi lathu. Ndi ma mbali yaikulu ya thupi lathu (pa chitukuko cha khalidwe ndi limafanana ndi mapuloteni zenizeni).

Kodi zigwirizana? Kapangidwe ka DNA imakhala mankhwala zovuta - nucleotides. Ndi chipika amatanthauza nyukiliotayidi kapena pawiri mini Ndikukhala akuphatikizapo m'munsi nitrogenous, otsala asidi phosphoric ndi shuga (Pankhaniyi - deoxyribose).

DNA ndi awiri Shackleton molekyulu, mmene aliyense madera zogwiritsidwa kwa ena mwa asafe zapansi za mfundo za mapolojekiti.

Komanso akhoza ankaganiza kuti DNA kumaphatikizapo majini - nyukiliotayidi linayamba kugawanika udindo kaphatikizidwe mapuloteni. ndi katundu mankhwala kapangidwe ka deoxyribonucleic acid ndi chiyani?

nyukiliotayidi

Monga tanenera, ichi chititsimikizira structural unit wa deoxyribonucleic acid ndi nyukiliotayidi. Izi ndi gulu zovuta. Zikuchokera zotsatirazi DNA nyukiliotayidi.

Pakati ndi zisanu chigawo nyukiliotayidi shuga (deoxyribose mu DNA ndi mosiyana RNA, muli ribose). Kuti izo wagwirizana m'munsi nitrogenous, amene n'kopanda mitundu 5: adenine, guanine, thymine, uracil ndi cytosine. Kuwonjezera apo, nyukiliotayidi wapangidwa ndi asidi zotsalira phosphoric.

Kapangidwe ka DNA imakhala nucleotides okhawo amene ali anasonyeza structural unit.

nucleotides onse anakonza mu unyolo ndi kutsatira mzake. Grouping a atatu (nucleotides atatu), iwo apanga zinayendera umene aliyense triplet lolingana ndi kwa amino asidi makamaka. Chifukwa ndi unyolo.

Iwo pamodzi mwa kugwirizana kwa zapansi asafe. ubwenzi zofunika pakati nucleotides kufanana madera - haidrojeni.

mindandanda nyukiliotayidi ndi maziko a chibadwa. Violation mu dongosolo lawo, zikubweretsa kulephera kaphatikizidwe mapulotini komanso chiwonetsero cha masinthidwe. Kapangidwe ka DNA imakhala majini chomwecho chimene kudziwa pafupifupi anthu onse ndi kusiyanitsa iwo ku zamoyo zina.

kusinthidwa wa nyukiliotayidi ndi

Nthawi zina, kwa kutengerapo wolimba wa khalidwe kusinthidwa wa nitrogenous m'munsi ntchito. The zikuchokera kwa DNA mankhwala akasintha ndi kuphatikana wa gulu methyl (CH3). Chotero kusinthidwa (nyukiliotayidi wina) zimathandiza ziziyenda jini akuti ndi makhalidwe kutengerapo maselo mwana wamkazi.

Izi "kusintha" a dongosolo la maselo sikumangotikhudza kucheza ndi zapansi nitrogenous.

kusinthidwa amagwiritsidwa ntchito ndi X-khromozomu inactivation. Chifukwa cha zimenezi, anapanga Barr thupi.

Mu nkhani ya kuchuluka kusanthula carcinogenesis DNA limasonyeza kuti unyolo nucleotides chinaperekedwa ku methylation pa magawo ambiri. Mu maphunziro taona, izo unkachitika kuti gwero la kusintha kwa nthawi zambiri methylated cytosine. Childs pa chotupa demethylation ndondomeko akhoza kulimbikitsa ndondomeko amasiya, koma chifukwa kapangidwe kake, anachita zimenezi si ikuchitika.

DNA kapangidwe

Mu dongosolo la molekyulu ndi mitundu iwiri ya nyumba. Yoyamba - ndi liniya ndondomeko ya nucleotides anapanga. yomanga awo umamumvera malamulo ena. Kujambulitsa pa nyukiliotayidi DNA akuyamba ndi 5'-terminus ndi 3'-terminus ikutha. Dera yachiwiri ili mwake, inamangidwa momwemo, okha mamolekyulu ndi spatially zosiyana wina ndi mnzake, mmene 5'-terminus unyolo wina lili moyang'anana ndi 3'-mapeto a lachiwirilo.

helix - DNA dongosolo sekondale. Chifukwa cha kukhalapo kwa nsinga wa hydrogen kuyambira pakati otsutsana nucleotides. Ubwenzi wa hydrogen aumbike (thymine yekha, guanine ndi kusiyana Mwachitsanzo, popenyana ndi woyamba timafupa adenine - uracil kapena cytosine) pakati zapansi wowonjezera nitrogenous. molondola chonchi chifukwa chakuti pomanga dera yachiwiri inachitika pa maziko a koyamba, kotero pakati pa zapansi nitrogenous pali machesi enieni.

Kaphatikizidwe wa molekyulu ndi

Kodi DNA anapanga?

Mu vuto la mapangidwe ake magawo atatu:

• Disconnection madera.
• Inalowa synthesizing mayunitsi mmodzi wa unyolo.
• Extension ku dera chachiwiri malinga ndi mfundo za mapolojekiti.

Pa siteji ya kulekana kwa mamolekyulu chimakhala chogwidwa ndi michere - DNA gyrase. michere awa lolunjika pa chiwonongeko cha kumangidwa wa hydrogen pakati unyolo.

Pambuyo unyolo divergence amabwera mu zofunika synthesizing enzyme - DNA polymerase. chotsatira kwambiri zimawonedwa pa malo 5. Kenako, enzyme ikuyenda kwa 3'-yotsiriza, imodzi kuika pa nucleotides zinafunika ndi zapansi yoyenera nitrogenous. Atafika osiyanasiyana anakonzeratu (Terminator) kumapeto 3, unyolo polymerase ndi sakukhudzidwa ndi gwero.

Kamodzi anapanga wocheperapo dera pakati zapansi ndi kupanga kumangidwa wa hydrogen, ndi chimene chikutsimikizira utangoyamba DNA.

Kodi ndingapeze molekyulu izi?

Ngati inu wofufuza kapangidwe ka maselo zimakhala, izo Tingaone kuti DNA ya makamaka opezeka phata selo. Ngale ndi udindo mapangidwe bulanchi latsopano, maselo kapena oyeserera awo. Choncho mudziwe majini azipereka m'menemo, nagawanika pakati pa maselo utangoyamba uniformly (kwaiye oyeserera) kapena pang'ono (zambiri anaona chodabwitsa zoterezi pa meiosis). Kugonjetsedwa kwa zotsatira pachimake mu kuphwanya mapangidwe minofu latsopano, imbaenda ku masinthidwe.

Komanso, mtundu wapadera chuma cholowa ali mitochondria lapansi. Iwo DNA osiyana penapake kuchokera ku phata (kwa mayitirokondiriyoni deoxyribonucleic acid ali ndi mawonekedwe annular ndipo amagwira ntchito zina zingapo).

Molekyulu yokha akhoza olekanitsidwa selo lililonse la thupi (phunziro la swab zambiri ntchito kuchokera mkati mwa tsaya kapena magazi). No zinthu majini okha epithelium ndi exfoliates ndi maselo ena magazi (erythrocytes).

ntchito

The zikuchokera kwa DNA ndiyo ntchito ya ntchito yake deta kufala ku mibadwomibadwo. Ichi ndi chifukwa kaphatikizidwe mapulotini ena chopatsa chiwonetsero cha genotype (mkati) kapena phenotypic (kunja - mwachitsanzo, mtundu wa maso kapena tsitsi) Mbali.

Kufala kwa mudziwe ikuchitika mwa kukhazikitsa malamulo ake majini. Pamaziko a deta encrypted mu malamulo chibadwa, pali chitukuko cha tsatanetsatane, ribosomal ndi kutengerapo RNA. Aliyense ali ndi udindo kwa kuchitapo kanthu - Mtumiki RNA ntchito lithe mapuloteni nawo mamolekyulu ribosomal mapuloteni msonkhano, ndipo ndipamene lolingana mapuloteni zoyendera.

kulephera aliyense mu ntchito kapena kukonza awo kusintha kumabweretsa kusokoneza ntchito anachita, ndi maonekedwe a mbali atypical (masinthidwe).

DNA bambo mayeso kudziwa pamaso zizindikiro ofanana pakati pa anthu.

mayesero majini

Kodi tsopano zitha kugwiritsidwa ntchito ndi kuphunzira zinthu majini?

DNA kusanthula ntchito kudziwa zinthu zingapo kapena kusintha mu chamoyo.

Phunziro loyamba kudziwa pamaso pa kobadwa nako, matenda akatengela apabanja. matenda monga ozerezeka, satha kulankhula bwinobwino, syndrome Marfan.

Kudziwa zimakhalira pachibale DNA akhoza kuphunzira. Bambo mayeso kalekale ambiri njira zambiri, makamaka malamulo,. Phunziro lino analamula kuti adziwe ubale majini pakati pa ana apathengo. Nthawi zambiri mayeso ntchito pochitika pa cholowa mwa mwambo mavuto akuluakulu.