DNA zamagama - kulula!

Ngisho eklasini biology, kodwa sathola ukuthi kwakuboshwe DNA - esiphathiswa jikelele kolwazi zofuzo zonke izidalwa eziphilayo, ngaphandle RNA amagciwane. DNA zamagama - inqubo lapho ludingeka ukudalwa entsha acid deoxyribonucleic.

Molecule ye-DNA elaqala ukutholwa maphakathi nawo kwekhulu lama-20, ososayensi ababili abayizifebe J. Watson Crick, zona, eqinisweni, wathola edumile uMklomelo KaNobel. Zona DNA - intambo double okuyinto osontekile ibe Kuvunguza. I lokuluhlaza yakhiwa nucleotide, ezixhunywe ku chungechunge. A nucleotide kuhlanganisa besisekelo esisodwa (nitrogen), okuyinto cytosine amane kuphela, ne-thymine, i-adenine ihambisane ne-guanine. Kuyinto lezi elisekela futhi ukuxhumana deoxyribose futhi zona kanye izisekelo iqembu phosphate unamathele.

DNA zamagama - lokhu akukona inqubo ezinzima, njengoba kungase kubonakale efika kuqala. Uma ucabanga ngakho, okokuqala udinga ukuqonda ukuthi yini iyona zamagama. Le nqubo yokuxuba lutho eyodwa. entsha DNA kumiswa senzeka ngezigaba eziningana:

1. DNA topoisomerase, eyayilele phambi ekuphambukeni ukufanisana, enquma DNA ukuze kube lula unwinding yayo futhi unwinding.
2. DNA helicase ngemva topoisomerase ezithinta inqubo "unwound" le Helix DNA.
3. amaprotheni DNA-ngibopha ngibopha imicu DNA wenziwa, nokuziphatha njengoba sinjalo zabo, ukuvimbela nabo kusuka ngokunamathela nomunye.
4. DNA polymerase synthesizes DNA osizayo phambili wesifunda.

Lezi zinyathelo ezine futhi ekupheleni zamagama, eligeleza okwenzeka engqamuzaneni umzali DNA. Kwasekusithi emva kwalezizinto, zamagama okusalele emuva wesifunda.

1. Ngemva imicu ye-DNA uzobe uhlaliseke njalo Unbraid DNA polymerase "-alpha" lizonamathiselwa ke lapho ubambe okuthiwa zamagama primer. Kufanele kuqashelwe ukuthi kulesi sigaba, lo synthesis RNA isinqamu. Lokho inqubo kumiswa DNA entsha Amangqamuzana angokwemvelo izidingo zomzimba futhi ribonucleotides. Ngemva kwezwi, enzyme esuswa imicu DNA, owawuke enamathiselwe. Enzyme elilandelayo ehambisana intambo, ngeke Epsilon DNA polymerase.
2. Enzyme oshiwo ngenhla uyaqhubeka andisa primer, kodwa isebenzisa kwalokhu deoxyribonucleotides, ribonucleotides kunokuba njengendlela-alpha-enzyme self-osesikhundleni. Lokhu kuphumela lonke uchungechunge lapho yakhiwa izingxenye ezimbili: i-DNA ne-RNA. Lokhu enzyme ibizwa asuswe uchungechunge uma etholwe owedlule primer isinqamu.
3. DNA polymerase "beta" ukususa esikhundleni ka ribonucleotides futhi deoxyribonucleotides kubo.
4. DNA ligase crosslinks izingcezwana ezimbili Okazaki. Ngaleso evala DNA zamagama. Lena esigabeni sokugcina yakhe.

Kungani sidinga zamagama-DNA futhi kungani le nqubo kubaluleke kangaka? Ukuze uqonde lokhu, kudingeka sizindle ngalokho okudingeka deoxyribonucleic acid kuphela. Umsebenzi wawo oyinhloko - ukugcinwa kolwazi zofuzo, okuzokwenza kamuva zidlulele inzalo. Kuyinto lo msebenzi futhi ibangwa ukubaluleka enjalo ephakeme DNA. Ngenxa yokuthi eliyosenza lonke ulwazi mayelana izakhi zofuzo, lapho ikhokhwa ekutadisheni Okubaluleke ngokukhethekile. Sithemba ukuthi ososayensi ngeke athole impumelelo enkulu lo mkhakha wesayensi.