1. C CH TI BN ADN V CCH TNG HP ARN Tn thnh vin nhm: Lu Th Duyn Nguyn Th Thy_1993 Ng Th Tuyt

2. Cu trc ca chui xon kp ADN Phn t ADNgm 2chuipolinucleotit lin ktvi nhau bng linkt hir gia ccbaz nit ca ccnucleotit theonguyn tc bsung : A lin kt viT bng 2 lin kthiro, G lin kt viX bng 3 lin kthiro. Lin kt Hir 3. - 2 chui polinucleotit ca ADNxon quanh trc tng tng,to nn xon kp u v ging 1 cu thang xon. 4. - Mi bc thang l 1cp baz nit, taythang l ng v axitphotphoric. - Khong cch 2 cpbaz nit l 0,34 nm(3,4 A0). Mi chu kxon c 10 cp Nu. 5. c im ca ADN- Bo qun v truyn t li thngtin di truyn. - C kh nng ti bn. - C th b t bin.ADN - C kh nng tng hp ARN.- Cu trc b sung cung cp s bov chng li s mt thng tin, boqun trong ADN. 6. Ti bn theo kiu bn bo ton v gin on: ADN con c1 mch ca ADN ban u. Gin on: c 1 mch c tnghp gin on to cc on Okazaki. Din ra theo nguyn tc b sung: A lin kt vi T v ngc li. G lin kt vi X v ngc li. Qu trnh ti bn ADN ph thuc vo mt h thng gmnhiu protein v enzym khc nhau. 7. Ti bn c bt u ti 1 hoc nhiu v tr c th trn phn t ADN v din ra ng thi theo hai hng ngc nhau gi l khi im ti bn 2 hng. Mi khi im ti bn vi hai chc ti bn nh vy gi l mt n v ti bn. i vi ADN mch vng, mi phn t ch c mt khi im ti bn, trong khi mi ADN trong nhim sc th Eukaryote c nhiu khi im ti bn hot ng theo mt trnh t c th.ADN virut dng thngPlasmid Phn ln c th sng 8. Kiu ti bn nh th gi l ti bn na gin on. S tng hp ADN khng lin tc di dng cc on Okazaki. Sau , cc on mi s c ct b v ch trng c thay bng ADN v cc on Okazaki c ni li bi emzym ADN ligase. 9. Cc enzym tham gia ti bn- Gyrase: lm gim sc cn bng ph v khng lintc cc lin kt phosphodiester. Thng c khong 10Nu th 1 lin kt b ph v.- Helicase: hot tnh ca helicase l c tnh caprotein AdnB v protein Rep, s kt hp ca 2 proteinny c gi l enzym helicase. Cc protein cng viprotein SSB tch ri hai si ca phn t ADN bngcch ph v lin kt Hir. 10. - ADN polymerase v primase: tng hp on ARNngn gi l mi.- ADN polymerase II, III: tng hp ADN chnh, c sa.- ADN polymerase I: c 3 hot tnh:+ To chui ADN.+ Ct chui ADN theo chiu 5-3.+ Ct chui ADN theo chiu 3-5 c v sa.- Ligase: ni cc on ADN trong qu trnh tibn, sa cha v ti t hp. 11. Nhng thnh phn tham gia ti bn ADN 1. Si ADN dng lm khun mu:Qu trnh tng hp cc si ADN mi cn c cc si ADNgc l khun.Cc nucleotit la chn ph hp cc nucleotit trn sikhun. Thng tin trn si ADN gc dng to thng tin trn sib sung. 12. 2. Cc Nucleosidetriphotphat: C 4 loi: ATP, TTP, GTP, CTP.3. Cc cation ha tr 2: Mg2+ 13. 4. Cc protein gn c hiu: - DnaA : Gn vo im khi u sao chp v khi u sao chp . - DnaC : To phc vi DnB ,thc y DnB lin kt vi ADN. - REP v DnB : gin xon ADN. - IHF v FIS : Prtin lin kt ADN. - TBP: dng chc sao chp. - SSB : ngn cn hai mch ADN lin kt b sung.5. Cc enzym c hiu 14. Giai on 1: Khi u: Ti ADN xon kp ni bt u s ti bn, ccprotein SSB xc nh v tr bt u nhn i v tchri hai mch ADN. Cc ADN helicase gn vi protein SSB xc nhv tr on u m xon kp, sau helicase cgii phng khi phc hp tip tc m xon to nnnh 1 ci da ch 2. Protein SSB gip 2 mch ADNkhng gn li vi nhau. ADN primase tng hp ADN mi gip choADN polymerase bt u tng hp chui ADN. 15. 16. - Trn si mu tnghp gin on: ADNpolymerase xc tcvic gn cc Nu vo mi tng hp nnon Okazaki. Ccon Okazaki chngcch nhau u n t100 n 200 Eukaryote v t1000 n 2000 vikhun. 17. Giai on 3: Kt thc: Ti si tng hp gin on: on mi b loi bbi enzym c bit. Vic loi b on mi to racc khong trng s c lp y bi ADNpolymerase v enzym gn ligase. Qu trnh trn gil qu trnh khi phc hon thin si ADN. Sau c s sa sai ca h thng enzym sa sailun r sot trn phn t ADN.=> Hnh thnh 2 phn t ADN con hon thin c lp 18. S nhn i sinh vt nhn thc nhn chung l gingsinh vt nhn s. Tuy nhin, c 1 vi im khc nglu :o - sinh vt nhn s ch c 1 im khi u sao chp (Ori C),nhng sinh vt nhn thc, do h gen ln, nn c rt nhiuim khi u ti bn.Pokaryote v vi khun Eukaryote 19. c im SV nhn sSV nhn thc- Chiu di cc on ARN - Di hn - Ngn hnmi v cc on Okazaki- Thi gian sao chp - Ngn (VD E. coli- Di hn ( thng 6 8 gi) l khong 40)- S im khi u sao - 1 im duy nht - Nhiu im ( VD: ngi c khongchp 20000 30000 im khi u sao chp trong ton h gen)- Tc sao chp - 850 nu / giy- 60 90 nu/giy- S loi enzym ADN - t ( VD: E.coli- Nhiu ( VD : ngi c t nht 15polimerase5 loi : ADN pol I,loi)II, III, IV, V)- Qu trnh sao chp ADN - Din ra lin tc v- Din ra giai on S ca chu trnh t ng thi vi qubo, din ra trong nhn t bo trong khi trnh phin m v qu trnh dch m din ra trong t dch mbo cht. 20. Phn loi gm: ARN di truyn v ARN khng di truyn.Theo cu trc v ch nng gm:mARN: ARNtARN: ARN vnrARN: ARN ARN nh trong thng tinchuyn riboxom nhn 21. mARN- Cu to dng mch thng, si n.- L bn sao cc b ba m ha trnADN, ng vai tr trung gian chuynthng tin m ha trn phn t ADNn b my gii m (ribxm) thnhphn t prtin tng ng.- Chim khong 2 - 5% tng s ARNca t bo. 22. tARN - Cu trc dng c ba l (dng ba thy), cu trc ny c n nh nh cc lin kt b sung mt s vng trn phn t tARN. - V tr khng c lin kt b sung hnh thnh cc thy, c vai tr c bit quan trng i vi chc nng ca tARN. 23. - Trnh t anticodon gm banucltit b sung cho codon (bba m ha trn mARN)- Trnh t Nu c kh nng hnhthnh lin kt cng ha tr viaxit amin c trng.- Vai tr vn chuyn cc axitamin cn thit n b my dchm tng hp prtin tmARN tng ng. 24. rARNoPhn t rARN c dng mchn, hoc qun li tng t nh tARNtrong d c ti 70% s ribonucleotit clin kt b sung. Trong t bo c nhnc loi rARN vi s ribonucleotit 160-13000.oMi ribxm gm hai tiu phn:tiu phn ln v tiu phn b.oCc rARN kt hp vi cc prtinchuyn bit to thnh ribxm, mtthnh phn ca b my dch m ca tbooChim 80% tng s ARN ca tbo. 25. ARN nh trong nhn Ct b nhng on intro v ni cc on extro 26. Mch khng lm khunARN polymerase Mch lm khun 27. c im chung ca Pokaryotev Eukaryote L phn ng sinh tng hp ARN trong t bo t khun ADN dinra di tc dng ca cc loi enzym ARN polymerase.ADN cha nhn c m xon cc b v thnh si n gi l sic tr c dng lm khun cho tng hp ARN.Phn ng tng hp ARN din ra theo nguyn tc b sung v kodi theo chiu 53 ngc chiu vs chiu ca si khun.Gm c 4 loi ribonucleosidetriphotphat: ATP, UTP, GTP, CTP.Cc ARN si n.S khi u kt thc phin m Ph thuc vo cc tn hiu iuha l cc trnh t ADN c th trc v sau gen c phin m. 28. Nhng giai on ca qu trnh phin mKhi u Gm c 3 giai on: Ko diKt thc 29. Khi u L s tng tc gia ARN polymerasevi vng Promoter nhm xc nh khunca ADN v tng hp vi nucleotit. Yu t tn cng s khi u mt cchchnh xc: nhn din on Nu c hiu khi ng phin m. Trong hai siADN c 1 si lm khun mu tham giatng hp ARN theo nguyn tc b sungkhi t ti di khong 10Nu th cutrc ARN polymerase thay i, chui bgii phng ri li gn v li 1 enzymkhc. 30. Ko di Khi to thnh phn t ADN- ARN giai on m u, li enzym di chuyn theo chiu dc ca phn t ADN tch hai si kp v cc ribonucleotit tip tc gn vo sau on ARN v c m u theo chiu 53. on ARN mi c tng hp tch khi ADN khun v hai si ADN ngng li khp li vi nhau. S lin kt ca cc ribnucltit t do vi cc nucltit trn mch khun mu ca gen cu trc theo nguyn tc b sung (A vi T ; U vi A ; G vi X v X vi G). 31. Kt thcTrong mt s trng hp s kt thc qu trnh phin mc thc hin vi s c mt ca yu t Rho yu t nygn vo ARN polymerase gip enzym nhn bit m ktthc.Trong mt s trng hp khng c s tham gia ca Rho.Yu t Rho c gii phng thc hin chu trnh mi.=> To thnh ARN bc 1. 32. So snh s phin m prokaryotev eukaryote Prokaryoye:o1 ARN polymerase tng hp tt c cc loi ARN.omARn thng cha nhiu ORF (nhiu gen, polycistron). Eukaryote:oVng mang m di truyn ca gen (exon) b gin on bi ccon khng mang m (intron).omARN c tng hp qua hai bc: tin mARN (pre mARN)v mARN trng thnh (mature mARN). 33. o Pre mARN c cha chp 7-methyl-guanosine u 5 v cha ui polyA (100-200 adenine) u 3.o Pre mARN c ch bin (splicing) loi b intro v ni cc exon li trc khi vo t bo cht.o mARN trong t bo cht cha thng tin lin tc.