Iyini i-DNA?

Isakhiwo Se-DNA kanye Nomumo

I-DNA, eyaziwa nangokuthi, i-deoxyribonucleic acid iyi-molecule, eyinqwaba yama-athomu anamathele ndawonye. Endabeni ye-DNA, lawa ma-athomu ahlanganiswa akhe ukuma kweladi elide elizungezayo. Singabona isithombe lapha ngokucacile ukuze sibone ukuma kwe-DNA.

Uma uke wafunda ibhayoloji, cishe wezwa ukuthi i-DNA isebenza njengepulani noma iresiphi yezinto eziphilayo. Kungenzeka kanjani emhlabeni ukuthi i-molecule nje ibe ipulani yento eyinkimbinkimbi futhi emangalisayo njengesihlahla, inja kanye nabantu? Kuyamangaza ngempela lokho.

I-DNA ingenye yeziqondiso eziyinhloko. Kuyinkimbinkimbi kakhulu kunanoma iyiphi indlela yokubhuka oke wayisebenzisa. Wonke umhlahlandlela wokufundisa ubhalwe ngekhodi. Uma ubhekisisa ukwakheka kwamakhemikhali e-DNA, izobonisa amabhlogo amane okwakha ayinhloko. Sibiza lezi zisekelo ezine-nitrogen: i-Adenine (A), i-Thymine (T), i-Guanine (G), ne-Cytosine (C). I-DNA ihlanganisa noshukela kanye namaqembu e-phosphate (enziwe nge-phosphorus nomoya-mpilo). Lezi zenza umgogodla we-phosphate-deoxyribose.

Uma ucabanga ngesakhiwo se-DNA njengesitebhisi, izingqimba zesitebhisi zenziwe ngezisekelo ze-nitrogen. Lezi zisekelo ziyabhanqa ukuze zenze isinyathelo ngasinye seladi. Baphinde babhanqa kuphela ngendlela ethile. (A) ihlezi ihambisana no-(T) kanye no-(G) ihlezi ihambisana no-(C). Lokhu kubaluleke kakhulu uma kuyisikhathi sokukopisha yonke noma ingxenye ye-DNA.

Ngakho, ukuze siphendule lo mbuzo, iyini i-DNA? I-DNA iyipulani yamangqamuzana ezinto eziphilayo. I-DNA idala i-RNA, futhi i-RNA idala amaprotheni, futhi amaprotheni aqhubeke enze ukuphila. Yonke le nqubo iyinkimbinkimbi, iyinkimbinkimbi futhi inomlingo futhi isekelwe ngokuphelele kumakhemikhali angafundwa futhi aqondwe.

Indlela yokuhlukanisa i-DNA Fragment?

NJENGOBA sathi i-DNA ingacwaningwa futhi iqondwe, kodwa singayenza kanjani? Ososayensi bayafunda futhi bacwaninge futhi bazihlole. Abantu basebenzisa i-gel electrophoresis ukuhlukanisa i-DNA ukuze kwenziwe ucwaningo olwengeziwe. I-Gel electrophoresis iyindlela esetshenziselwa ukuhlukanisa izingcezu ze-DNA (noma amanye ama-macromolecules, njenge-RNA namaprotheni) ngokusekelwe kusayizi nokushaja kwazo. I-Electrophoresis ihilela ukusebenzisa i-current ngokusebenzisa ijeli equkethe ama-molecule athakazelisayo. Ngokusekelwe kubukhulu bawo kanye nokushajwa kwawo, ama-molecule azohamba ejeli ezindaweni ezihlukene noma ngesivinini esihlukene, okuwavumela ukuba ahlukaniswe amanye. Ngokusebenzisa i-electrophoresis, singabona ukuthi zingaki izingcezu ze-DNA ezikhona kusampula nokuthi zinkulu kangakanani uma ziqhathaniswa nezinye.

Uma ufuna ukwenza i-electrophoresis ye-gel, okokuqala udinga imishini yokuhlola ehlobene, iseli ye-electrophoresis (ithangi/igumbi) kanye nokunikezwa kwamandla ayo. Isithombe esilandelayo sibonisa iseli ye-electrophoresis evundlile (ithangi/igumbi) imodeliI-DYCP-31DNkanye nemodeli yamandlaI-DYY-6Devela e-Beijing Liuyi Biotechnology Co., Ltd ye-DNA gel electrophoresis.

I-Gel electrophoresis ihilela ijeli, okuwuhlobo lwezinto ezifana ne-Jello. Amajeli okuhlukaniswa kwe-DNA avame ukusetshenziswa i-agarose, eza njengama-flakes omile, ayimpuphu. Lapho i-agarose ishiselwa endaweni egcina amanzi (amanzi anosawoti othile kuyo) futhi ivunyelwe ukuba iphole, izokwakha ijeli eqinile, ehlaza kancane. Ezingeni lamangqamuzana, ijeli iyi-matrix yama-agarose ama-molecule ahlanganiswe ndawonye ngamabhondi e-hydrogen futhi akhe izimbotshana ezincane.

Isithombe esivela ku-Khan Academy

Ngemva kokulungisa ijeli, faka ijeli emzimbeni wethangi leseli ye-electrophoresis, bese uthela isisombululo se-buffer ethangini le-buffer kuze kube yilapho ucwiliswa ijeli. Khona-ke amasampula e-DNA alayishwa emithonjeni (ama-indentations) ekugcineni kwejeli, bese kusetshenziswa umsinga kagesi ukuwadonsa ngejeli. Izingcezu ze-DNA zikhokhiswa kabi, ngakho-ke ziya ku-electrode enhle. Ngenxa yokuthi zonke izingcezu ze-DNA zinenani elifanayo lokushaja ngesisindo ngasinye, izingcezu ezincane zihamba ejeli ngokushesha kunezinkulu. Ngemva kokugijima i-gel electrophoresis, izingcezu ze-DNA ziye zahlukaniswa; futhi abacwaningi bangahlola ijeli futhi babone ukuthi yimaphi amasayizi amabhande atholakala kuyo. Uma ijeli ingcoliswe udayi obopha i-DNA futhi ibekwe ngaphansi kokukhanya kwe-UV, izingcezu ze-DNA zizokhanya, okusivumela ukuthi sibone i-DNA ekhona ezindaweni ezihlukene ngobude bejeli.

Ngaphandle kwamaseli e-electrophoresis (amathangi/amagumbi) nezinto zikagesi, i-Beijing Liuyi Biotechnology Co., Ltd futhi ihlinzeka nge-UV transilluminator, ekwazi ukubona futhi ithathe izithombe zejeli ye-protein ne-DNA electrophoresis. ImodeliI-WD-9403Biyi-transilluminator ephathekayo ye-UV yokubheka ijeli ye-DNA electrophoresis. ImodeliI-WD-9403Fangabona, athathe izithombe zakho kokubili amaprotheni kanye nejeli ye-DNA.