Kapangidwe ka DNA ndi RNA kapangidwe

Ngati ife kulingalira maonekedwe a munthu DNA izo akufanana zopotoka mwauzimu, amene anapanga ndi maunyolo awiri polynucleotide amene anapotoza pakati pa iwo ndi imodzi padziko imodzi nkhwangwa awo wamba.

Childs, kapangidwe DNA imatengedwa mwa dongosolo kusanthula momwe monga waukulu - ali mosamalitsa amodzi (kwa yachibadwa chikhalidwe) Ndondomeko interposition dezoksiribonukleozidmonofosfatov - dNMP, zigawo polynucleotide unyolo.

Mu sanali mutated selo mononucleotides anagwirizana nsinga phosphodiester, ndi iwo eni kutsekedwa polynucleotide unyolo ndi yachiwiriyo kwa malo a magulu kwenikweni pa 5'-mapeto a unyolo ndi mankwala gulu, ndi gulu HA ndi mu dera Z'-yotsiriza.

Ngati tikambirana molekyulu ongokhala m'magawo awiri, kapangidwe DNA ndi chotero kuti unyolo polynucleotide adzakhala antiparallel kwa wina ndi mzake. M'dera izi anapitiriza mu dongosolo chotero chidzakhala chifukwa nsinga wa hydrogen kuti chikhalepo pakati pa zapansi A-T ndi GC, coplanar, perpendicular kwa olamulira waukulu mamolekyulu ndi mwauzimu. Anthu ankachita hydrophobic, anapanga pakati pa zapansi umenewu molekyulu, wokhazikika kudutsa helix awiri. Pakuti molekyulu, kapangidwe ka DNA yodziwika ndi mapolojekiti unyolo polynucleotide, koma si kuti ndi nyukiliotayidi awo zikuchokera losiyana.

Komanso, popeza kuti ndi dongosolo DNA, tisaiwale kuti aliyense molekyulu mmodzi "odzaza" mu mosamalitsa wapadera, khromozomu osiyana. DNA zimenezi zimakhala zosiyanasiyana mapulotini zizigwirizana zinayendera mosamalitsa kumatanthauza ya kapangidwe DNA. mapulotini awa ali m'magulu m'magulu 2: histones ndi mapuloteni negistony. Mu zovuta ndi DNA nyukiliya maselo, mapuloteni awa otchedwa chromatin.

Pofotokoza kapangidwe ka DNA, tisaiwale kuti chromatin tichipeza mitundu isanu ya histones, chiwerengero mlandu zabwino zomwe imapereka amphamvu kwambiri chomangira histones ndi DNA. Zovuta za histones ndi tizidutswa DNA kumatanthauza gawo kamodzi 146 nyukiliotayidi awiriawiri, ndi anachita, zimene amapanga nucleosomes.

M'gulu kapangidwe ka mapuloteni DNA negistony kuimira zosiyanasiyana mitundu ya mapuloteni zolimbana, kugwirizana ndi mbali makamaka DNA. Komanso, DNA mamolekyulu Kugwirizana kwa kapangidwe ka michere kupereka biosynthesis.

Phunziro kapangidwe ka DNA ndi RNA mwa kusanthula dongosolo ayenera kukhala zovuta, kuti ali tikaonetsetsa Kapangidwe ka DNA, m'pofunika kuganizira kapangidwe ndi RNA.

Kapangidwe zake zikuluzikulu, komanso nkhani ya DNA ndi aligorivimu interlace ribonukleozidmonofosfatov, motero, kuti n'komwe kuti, mosiyana ndi DNA, mitundu yonse ya RNA kokha unyolo imodzi polynucleotide lapansi. Mu Kapangidwe ka RNA molekyulu ndi chingwe chake umodzi anapanga, wotchedwa "hairpin" - spiralized zingwe zopota amene ali Au ndi GC m'munsi ndi okhazikika mwa mgwirizano wa hydrogen.

Childs, ambiri waukulu DNA limapangidwa pafupifupi 150 nyukiliotayidi awiriawiri millionov, ndi m'litali ndi masentimita anayi. Laboratory kusanthula mamolekyulu ngati kungakhale kovuta kwambiri kuphunzira, chifukwa pamene ndi Kugawilidwa kwanthaka wa minofu, molekyulu amamuchititsa kwambiri unagawanika ndipo kukhala laling'ono kwambiri mu kukula. Kuthetsa mavuto lino, maphunziro ndi njira PCR - kuchititsa polymerase unyolo anachita, imene ndi kusankha synthesizing zigawo munthu wa DNA, ndi kuonetsetsa maphunziro zofunika zidutswa zake.