Shaqooyinka DNA iyo qaab-dhismeedka

Wadnaha ee unugyada nool ee noolaha maarmin yihiin hawlaha polymers noolaha, acids nucleic, carbohydrates, borotiin iyo subaga. Biopolymers ka kooban yihiin monomers, dhismayaasha shidaalka, kaas oo sidoo kale ka mid ah nitrogen, oxygen, baaruud iyo fosfooraska.

Qarnigii 19aad, daraasadda of qaabka walxaha la bilaabay in noqonaya unug nool, laakiin shaqo ee DNA, borotiinada, RNA, iyo qaab-dhismeedka waxaa ugu dambeyntii goostay in qarnigii 20-aad.

Friedrich Miescher ee 1868, go'doon ka nuclei cell leukocytes phosphorous oo wuxuu u yeedhay waxaa nukleina. Markaas Richard Altman 1889 go'aamisay in walax this ka kooban acids gaarka ah iyo protein. Markaas markii ugu horeysay oo maqlay oo ku saabsan ereyga "acid nucleic". Si kastaba ha ahaatee, in la dhiso shaqada ee acids nucleic weli fog.

DNA - deoxyribonucleic acid - waa polymers ugu weyn noolaha ka kooban boqolaal monomers - deoxyribonucleotides. In ay ka kooban marka laga reebo sonkorta (deoxyribose), waxaa ka mid ah 4 noocyada kala duwan ee nucleotides: adenayn - A, thymidine - T, saytosayn - C, gu'anayn - G.

Marka ugu horaysa waxaa loo tixgeliyaa a DNA acid nucleic isir xoolaadka ah, tan iyo markii go'doonsan ka thymus xoolaha, iyo RNA waxaa go'doonsan ka jeermiga sarreen ah - cuntada. Waxaa la rumeysan yahay in garoonka la soo dhaafay farqiga u lagmamaarmaanna u dhexeeya unugyada jinsiyadaha laga helay teny iyo xayawaanka. Si kastaba ha ahaatee, in bartamihii qarnigii labaatanaad, waxay heleen in RNA iyo DNA ku jira unugyada oo dhan.

Isla-dhismeedka bilaabay barashada acids nucleic Erwin Chargaff, kuwaas oo sanadkii 1953 lagu ogaaday in nucleotides in ay yihiin qayb ka mid ah la joogto adag oo laba laba qaab magaca acid isla.

xiriir mar walba qaataan hal pyrimidine iyo purine saldhig ka mid ah, T = C, A = T. Taasi waa, adenayn xidhana in thymidine iyo gu'anayn - la saytosayn.

Oo function DNA muhiim ah in xidhiidhka kiiska ugu horeysay bixinta hydrogen 2-labo, iyo tan labaad - saddex.

xeerarka Chargaff ayaa cadeeyay saldhig on taas oo Watson oo Crick dhisay qaab-dhismeedka of DNA galool labanlaab.

In Britain this, iyo sidoo kale in u taagoo protein, hoose oo kala duwan, qaab-dhismeedka Dugsiyada Sare iyo Jaamacadaha.

Qaab-dhismeedka hoose - isku xigxiga oo toosan ee monomers Silsilad isku.

Dabcan, in nooca DNA ee hal silsilad ma dhici karto, laakiin halkan waxaan ka hadleynaa qaab dhismeedka hoose ee biopolymers, kaas oo qeexaya dhammaan hantida.

Qaab dhismeedka Secondary - dabeecad u da'ayeen of biopolymer ah. In the case of DNA waa polynucleotide ah laba silsiladood, mid kasta oo la qaloocdo in galool a midig, labaduba waa isku mar qaloocdo in jihada a bilow ah oo ku saabsan dhidibka caadi ah. silsilado waxaa lagu qabtaa soo socota si ay ciidamada of lagala kulmo hydrogen. Dhismaha jaamacadda oo ka mid ah u taagoo galool DNA sii qeexay.

Weeraryahanka tallaabo A Rafaa la sameeyey iyadoo la ogaaday in shaqo ee DNA waa in lagu wareejiyo iyo kaydinta macluumaadka hidaha. DNA ku jira barnaamijka hidaha ee qaab dhismeedka of borotiinada, gaar ah u shaqeeyo mid walba. Waxay, oo ay weheliso taagoo RNA ah Gaadhsiin macluumaadka hidde ka shaqeeyo in u shaqeeyo. DNA ayaa sidoo kale mas'uul ka ah hirgelinta iyo macluumaad hidde waa. Waxay ku lug leedahay geeddi-qoraal, tarankooda iyo turjumidda, sidaas hubinta ereygu wuxuu ahaa ee borotiin kala duwan.