Imisebenzi ye-DNA kanye oyiyo

Ngesikhathi inhliziyo zamangqamuzana aphilayo ayizinhlobo eziphilayo imisebenzi ebalulekile kukhona nemisebenzi polymers begazi, acid nucleic, ama-carbohydrate, amaprotheni lipids. Biopolymers aqukethe monomers, hydrocarbon izakhiwo, nakho zihlanganisa i-nitrogen, umoya-mpilo, isibabule ne phosphorus.

Ekhulwini le-19, lapho kutadishwa isakhiwo izinto seluqaliwe ukuthi umthetho kwengqamuzana ephilayo, kodwa umsebenzi we-DNA, amaphrotheni, i-RNA, nokwakheka kwawo ekugcineni kunqunywa ekhulwini lama-20.

Friedrich Miescher e 1868 ukuzihlanganisa iseli nuclei phosphorous leukocyte walibiza ngokuthi nukleina. Khona-ke Richard Altman ngo-1889 wanquma ukuthi yalolu ketshezi siqukethe acid akhethekile amaprotheni. Khona-ke okokuqala futhi wezwa igama elithi "nucleic acid". Nokho, ukusungula umsebenzi of acid nucleic ukuthi isekude.

DNA - deoxyribonucleic acid - iyona polymers ngobukhulu yemvelo yakhiwa monomers amakhulu - deoxyribonucleotides. Ngo Ukwakheka kwabo ngaphandle ushukela (deoxyribose), kuhlanganisa 4 izinhlobo nucleotide: i-adenine - A, thymidine - T, cytosine - C, i-guanine ne - G.

Okokuqala kwakubhekwa njengesibusiso DNA nucleic acid okuvela ezilwaneni, selokhu behlukene thymus kwezilwane, futhi i-RNA ahlukanisa kusukela kakolweni lwegciwane - zemifino. Kukholakala ukuthi ekugcineni umehluko kwamakhemikhali phakathi izinhlanga amaseli atholakele teny nezilwane. Nokho, phakathi kwekhulu lamashumi amabili bathola ukuthi i-RNA futhi DNA afakiwe wonke amaseli.

Ngokushesha isakhiwo waqala ukutadisha acid nucleic Erwin Chargaff, ngubani ngo-1953 yathola ukuthi ama-nucleotide ayingxenye okufanayo negama acid ifomu ngazimbili njalo esiqinile.

Uxhumano njalo uthathe esisodwa pyrimidine futhi purine kumila omunye, T = C, A = T. Lokho, adenine sibopha ukuthi thymidine futhi i-guanine ne - ne-cytosine.

Futhi umsebenzi DNA ezibalulekile uxhumano esimweni sokuqala ukuhlinzeka i-hydrogen 2 ngazimbili, kanti eyesibili - ezintathu.

imithetho Chargaff waphelela isizinda lapho Watson Crick eyakhelwe isakhiwo se-DNA double helix.

Kulesi molecule kanye amaprotheni amangqamuzana, eyinhloko ezahlukene, izakhiwo nemayunivesithi.

Isakhiwo eyinhloko - ukulandelana komugqa monomers e yochungechunge olufanayo.

Yiqiniso, ngokwesimo iDNA uchungechunge olulodwa ingekho, kodwa lapha sikhuluma isakhiwo eyinhloko biopolymers, okuyinto uchaza yonke impahla yayo.

isakhiwo sesibili - isici kwezendawo biopolymer. Endabeni DNA kuba polynucleotide ngamaketanga amabili, ngalinye elikwazi osontekile endaweni Helix kwesokudla, futhi kokubili kanyekanye basonta ohlangothini ngokwewashi mayelana eksisi ezivamile. Lezi amaketanga aphethwe eduze amabutho hydrogen kunenze nisondelane. Isakhiwo neliphezulu molecule e-DNA Helix okwengeziwe echaziwe.

Isinyathelo elikhulu eliya phambili senziwa ne ukutholakala ukuthi umsebenzi DNA ukuze uthumele futhi isitoreji solwazi zofuzo. DNA iqukethe uhlelo kwezakhi isakhiwo amaprotheni, ethize umzimba ngamunye. Wona, kanye nawo amangqamuzana RNA idlulisele ukwaziswa kwezakhi zofuzo kusuka umzimba ukuze umzimba. I-DNA futhi lababukene nekwetfulwa futhi ukwaziswa kwezakhi zofuzo. Ababandakanyeka umbhalo izinqubo, ukufanisana kanye translation, ngaleyo ndlela ukuqinisekisa synthesis amaprotheni ahlukahlukene.