Deoxyribonucleic acid. Model Crick ndipo Watson

Mfundo yoyamba za katundu mankhwala deoxyribonucleic acid ali pachibwenzi 1868 chaka. M'zaka za m'ma 20 mpaka chiyambi cha makumi anai, iwo anali atatsimikizira kuti molekyulu ndi liniya polima. Monga nucleotides monomer mayunitsi imene imakhala m'munsi nitrogenous, ndi pentose ndi mankwala gulu (a zisanu mpweya shuga).

deoxyribonucleic acid akhoza kukhala m'munsi mwa mitundu iwiri: a pyrimidine (thymine (T) ndi cytosine (C)) ndi purine (adenine (A) ndi guanine (G)). Pawiri ikuchitika ntchito nyukiliotayidi phosphodiester muzikondana.

Akatswiri Watson ndipo Crick mu chaka 1953, kutenga monga maziko X-ray kusanthula timibulu DNA anapeza kuti molekyulu mbadwa tichipeza awiri unyolo polima, n'kupanga helix awiri. Polynucleotide unyolo bala pa wina ndi mzake, ikuchitikira pamodzi mwa kumangidwa wa hydrogen amene amapanga pakati wowonjezera zapansi (matanthauzo lolingana) maunyolo zosiyana. Pamene awiri izi atangotha motere: adenine-thymine, guanine-cytosine. Olimba ikuchitika ndi awiri awiriawiri loyamba ndi lachiwiri - atatu nsinga wa hydrogen.

Asidi awiri Shackleton deoxyribonucleic ali kutalika masamu chiwerengero cha awiriawiri nucleotides matanthauzo lolingana (BP). Pakuti mamolekyulu zimenezo zimene zigwirizana mamiliyoni ndi zikwi mabanja m.n.p. mayunitsi anatengedwa ndipo KB, motero. Choncho, deoxyribonucleic asidi khromozomu anthu ukufanizidwa ndi helix munthu wachiphamaso. m'litali ndi 263 MB mu

DNA denaturation (limatsogolera) ndi ndondomeko limene nthawi zonse awiri helix liniya molekyulu akudutsa mu boma koyilo. Pa kusungunuka, awiri molekyulu lagawidwa dera osiyana. Kutentha pa zomwe theka deoxyribonucleic asidi kusungunuka, ndi mfundo kusungunuka. Izo zimatengera mtundu wa zikuchokera maselo.

Monga tanenera kale pamwambapa, G-C awiriawiri ndi okhazikika ndi atatu, ndipo atavala A-T - awiri nsinga wa hydrogen. Choncho, ndi apamwamba chiwerengero cha awiriawiri woyamba, wolimba adzakhala molekyulu. Pamene denaturation wa timaganiza za 260 nm kumawonjezera mayamwidwe wa kuwala. Amenewa hyperchromic limachititsa kupereka ulamuliro pa boma maselo a dongosolo yachiwiri. Ngati njira pang'onopang'ono utakhazikika asidi osungunula pakati pa chingwe wowonjezera limasonyeza ofooka akhoza kupangidwa kachiwiri, kungakhale dongosolo mwauzimu ndi zofanana kwa mbadwa (pachiyambi). Luso limeneli kwa DNA denaturation ndi renaturation mamolekyulu zochokera mwakusakaniza njira. Izo ntchito pophunzira kapangidwe zidulo mkati.

-Kawiri helix molekyulu, kukhala chonyamulira deta chibadwa, amafunika ziwiri zazikulu. Choyamba, tiyenera chitidwe (chinaonekeranso) molondola mkulu, ndipo kachiwiri, kuti encode kaphatikizidwe wa zedi. deoxyribonucleic acid, zomwe chitsanzo wakhala anafotokozedwa ndi Watson ndipo Crick, wolingana ndendende ndi zofunika zimenezi. Umapezeka kuti malinga ndi mfundo za mapolojekiti, aliyense unyolo mu molekyulu ungakhale masanjidwewo mapangidwe latsopano dera lochitira lolingana. Chifukwa, gawo limodzi la kugawanika Choncho amapezeka awiriwiri ndi mnyamata mwana mamolekyulu kukhala nyukiliotayidi ndondomeko zofanana ndi zimene oyambirira DNA. Ndiponso, izi unyolo structural jini mu ndiyotengera mapuloteni zinayendera kwa amino asidi amakhazikitsa.

Popeza, monga chaonekera DNA anthu kutsegula ndi mapolojekiti ena mfundo, anakhazikitsa njira kuti ali ndi udindo deta cholowa decoding ndi lamulo la jini kaphatikizidwe zinthu. Komanso chiphunzitso anayamba kupanga ndi mamolekyulu zophatikizananso.