Ntchito ya DNA ndi matabwa ake

Pa mtima wa maselo a zamoyo ntchito yofunika udindo wa ma polima zamoyo zidulo mkati chakudya, mapuloteni ndi lipids. Biopolymers zigwirizana monomers, hydrocarbon nyumba, amene mulinso asafe, mpweya, sulfure ndi phosphorous.

M'zaka za m'ma 19, kuphunzira kapangidwe ka zinthu anali atayambitsa zomwe zimapanga selo lamoyo, koma ntchito ya DNA, mapuloteni, RNA, ndi kapangidwe awo potsiriza anatsimikiza za zana la 20.

Friedrich Miescher mu 1868, kutali selo mtima phosphorous leukocytes n'kulitcha nukleina. Kenako Richard Altman mu 1889 anatsimikiza kuti mankhwala tichipeza zidulo wapadera ndi mapuloteni. Kwa nthawi yoyamba ndipo anamva mawu akuti "asidi mkati". Komabe, kukhazikitsa ntchito zidulo mkati anali akadali kutali.

DNA - deoxyribonucleic acid - ndi yaikulu kwachilengedwenso ma polima wapangidwa monomers mazana - deoxyribonucleotides. Mu zikuchokera awo kupatula shuga (deoxyribose), muli mitundu 4 nucleotides: adenine - A, thymidine - T, cytosine - C, guanine - G.

Nthawi yoyamba ankaona DNA mkati asidi chiyambi nyama, popeza anali olekanitsidwa ndi thymus za nyama, ndi RNA anali olekanitsidwa nyongolosi tirigu - masamba. Iye akhapidziwa kuti pomaliza kusiyana amuzolengedwa pakati pa maselo mitundu anapezeka teny ndi nyama. Komabe, pakati pa mazana makumi awiri anapeza kuti RNA ndi DNA aphatikizidwa maselo onse.

Nthawi yomweyo kapangidwe anayamba kuphunzira zidulo mkati Erwin Chargaff, amene mu 1953 anapeza kuti nucleotides amene ali mbali ya dzina lomweli asidi mawonekedwe awiriawiri ndi zonse okhwima.

kugwirizana nthawi zonse mmodzi pyrimidine ndi purine m'munsi mwa munthu, T = C, A = T. Ndiko kuti, adenine chimamanga kuti thymidine ndi guanine - ndi cytosine.

Ndipo ntchito DNA zofunika kuti kulumikizana mu yoyamba kupereka wa hydrogen awiriawiri 2, ndipo chachiwiri - atatu.

malamulo Chargaff anasonyeza m'munsi limene Watson ndipo Crick anamanga Kapangidwe ka DNA awiri helix.

Mu molekyu imeneyi, komanso zedi, chachikulu osiyana, nyumba zasekondale ndi ukachenjede.

Kapangidwe chachikulu - ndi liniya ndondomeko ya monomers mu unyolo chomwecho.

Kumene, mu chikhalidwe cha DNA mu unyolo limodzi zimachokeradi, koma apa tikukamba za dongosolo yaikulu ya biopolymers, amene imalongosola onse katundu wake.

Secondary kapangidwe - ndi okhudza malo khalidwe la biopolymer lapansi. Pankhani ya DNA ndi polynucleotide maunyolo awiri, omwe wokhota mu helix lamanja, ndi zonse ziwiri nthawi imodzi anapotoza m'njira mobwerera za olamulira wamba. maunyolo awa ikuchitikira pafupi ndi mphamvu za mgwirizano wa hydrogen. Kapangidwe ukachenjede ya mamolekyulu DNA helix zina kumatanthauza.

Chinthu chimphona patsogolo anapangidwa anatulukira kuti ntchito ya DNA ndi kusamutsa ndi kusunga mfundo chibadwa. DNA muli pulogalamu majini a kapangidwe ka mapuloteni, yeniyeni aliyense chamoyo. Iwo, pamodzi ndi mamolekyulu ndi RNA popereka mauthenga a majini kwa chamoyo ndi chamoyo. DNA ndi udindo kukhazikitsa ndi mfundo majini nayenso. Iwo PALI njira galamafoniyo, kugawanika ndi translation, motero kuonetsetsa kaphatikizidwe mapulotini zosiyanasiyana.