Yuav ua li cas yog DNA, dab tsi yog nws muaj nuj nqi thiab tseem ceeb rau muaj sia nyob

DNA - ib tug deoxyribonucleic acid, uas muab kev ruaj ntseg thiab cov kis ntawm kev tshuaj ntsuam genetic ntaub ntawv. Nyob rau hauv nws cov qauv lub encrypted ntaub ntawv nyob rau hauv cov qauv ntawm cov RNA thiab proteins ntawm lub cev. Qhib cov qauv no Swiss I.Mishlerom nyob rau hauv 1869.

Ua ntej, lub tiag tiag thaj chaw ntawm DNA tau paub. Nws twb ntseeg tau hais tias nws yog lub luag hauj lwm rau kev tswj lub cev ntawm phosphorus thiab nws cov khoom mus rau kis ntaub ntawv yog tsis txawm paub, vim hais tias muaj ntawm roj ntsha ntaub ntawv feeb xam tau tias yog proteins. Tsuas yog nyob rau hauv 1944, tom qab ib tug series ntawm thwmsim rau lub transformation ntawm cov kab mob, nws yog pom hais tias xws li DNA, thiab qhia tau nws yooj yim zog. Tom qab 1952 cov lus qhia txog qhov no molecule widened - nws los ua npe hu hais tias nws yog lub ntsiab cab kuj ntawm cov ntaub ntawv hais txog cov qauv ntawm cov genotype (lub teeb ntawm cov noob nyob rau hauv ib tug kab tsiaj txhuv), tab sis tsis paub dab tsi thaum lub sij hawm ntawm nws heev qauv, cov qauv ntawm cov DNA yog tsis transcribed.

Nws molecular qauv twb deciphered nyob rau hauv 1953 los ntawm James Watson thiab Francis Crick. Lawv txiav txim hais tias qhov no DNA - molecule tsim ib ob helix muaj deoxyribose thiab phosphate pawg, uas khi nitrogenous bases - adenine, cytosine, guanine thiab thymine.

Nws yuav tsum tau muab sau tseg tias thaum lawv tseem cov hauv paus ntsiab lus muaj ib tug kom meej meej tseg txoj kev - adenine uake nrog thymine thiab guanine nrog cytosine, uas saib kuas muaj tseeb thiab yog nws tus kheej-replication ntawm cov DNA molecule raws li lub hauv paus ntsiab lus ntawm complementarity nrog ib tug ntawm nws cov subsidiaries qwj.

Xws li ib tug ntshiab qhia kom paub txog cov molecular qauv tau enabled ib tug zoo dua kev nkag siab txog dab tsi lub DNA - cov qauv uas preserves cov kev tshuaj ntsuam genetic code yog lub hauv paus ntawm caj nyob rau hauv tag nrho cov uas muaj sia nyob, nrog rau eukaryotes thiab ib co kab mob.

Cov kev tshuaj ntsuam genetic code yog muab raws li ib tug kev nucleotide ib theem zuj zus. Yog li, txhua amino acid protein encoded los ntawm peb cov nucleotides thiab cov kua qaub ib theem zuj zus yog ib tug noob.

Yog hais tias muaj kev hloov tshwm sim nyob rau hauv cov qauv ntawm cov DNA point hloov los yog noob. Point mutational hloov nyob rau hauv lub molecular qauv yog tsoo, uas yog ib qho yooj yim mus ntes los ntawm biochemical los yog hybridological tsom xam. Noob change tshwm sim thaum hloov cov interleaving nucleotides, uas yog lub txiaj ntsim ntawm dab xws li zaus, transversions, zoo los yog poob ntawm ib tug neeg los luj officers, uas ua txhaum cov kev hauj lwm thiab thaj chaw ntawm DNA.

Yog hais tias cov yam ntxwv hloov ua rau lub distortion ntawm qhov tseem ceeb qhov chaw ntawm lub polypeptide nyob rau hauv tus kab mob muaj mob loj ua txhaum, uas txiav txim tsis tau tsuas yog ib tug ua txhaum ntawm kev loj hlob ntawm tus kab mob no, tab sis kuj kom lawv puas tsuaj. Piv txwv li, change yuav tshwm sim txawm thaum lub sij hawm me nyuam hauv plab kev loj hlob, yuav ua tau rau yug me nyuam ntawm tuag los yog uas tsis yog-zaum cov me nyuam. Nyob rau hauv tas li ntawd, xws ua txhaum cai yog lub plawv ntawm ntau yug tsis xws luag uas muaj peev xwm yuav kis tau mus rau yav tom ntej tiam.

Yuav kom saib lub ntsab lug, nws muaj peev xwm yuav xaus lus li mus rau lub DNA uas yog - nws tseem ceeb heev qauv ntawm caj ces, uas yog lub ntsiab tivthaiv ntawm chromosomes. Nyob rau hauv tas li ntawd, DNA - acid, uas yog lub luag hauj lwm rau kev siv cov kev tshuaj ntsuam genetic ntaub ntawv thiab cov hauj lwm uas muaj sia nyob.