Ukuphindaphinda kweDNA yindlela ephambili

Ukuphindaphinda kweDNA yinkqubo ye-biosynthesis ye-deoxyribonucleic acid. Izinto eziphathekayo kwi-biosynthesis ye-DNA yi-adenosine, i-guanosine cytidine kunye ne-thymidine triphosphoric acid okanye i-ATP, i-GTP, i-CTF ne-TTF.

Indlela yokuphindaphinda i-DNA

I-biosynthesis iqhutyelwa phambi kwento okuthiwa "imbewu" - inxalenye ethile ye-deoxyribonucleic acid engatshintshiyo kunye ne-catalyst. I-DNA polymase isebenza njengento ekhuthaza. Le enzyme ithatha inxaxheba ekudibaneni kweentsalela ze-nucleotide. Amanxuwa angamawaka ama-nucléotide axhunyiwe ngomzuzu omnye. Izinsalela ze-nucleotide kwi-molecule ye-deoxyribonucleic acid fragment zidibene kunye nama-3 ', 5'-phosphodiester bonds. I-DNA polymasease ichithisa ukudibanisa kwee-mononucleotide eziseleyo ekupheleni kwe-3-hydroxyl ekupheleni kwe-deoxyribonucleic acid. Okokuqala, iinxalenye ezincinci ze-molecule ye-DNA zenziwe. Ziboleke kwiDNA ligase kwaye zenze iinqununu ezide ze-deoxyribonucleic acid. Zomabini iziqhezu zendawo zihlala kwiinuclei zeeseli. I-deoxyribonucleic acid eguqulwayo isetyenziswe njengendawo yokukhula kwe-molecule ye-DNA kunye ne-matrix apho i-dioxyribonucleic acid edibanisa ngayo, efana ne-DNA eguqulelwe kwisakhiwo kunye nokulandelelana kwezinsalela ze-nucleotide. Ukuphindaphinda kwe-DNA kwenzeka ngexesha lokwahlukana kwesahlulo se-cell mitotic . I-Deoxyribonucleic acid igxininiswe kuma-chromosomes kunye ne-chromatin. Emva kokubunjwa kwe-single-stranded deoxyribonucleic acid, izakhiwo zayo zesekondari kunye nezisemgangathweni zenziwa. Amacandelo amabini e-deoxyribonucleic acid ahlangene kunye nezibophezelo ze-hydrogen ngokwemigaqo yokulungelelaniswa. Ukuphindaphinda kwe-DNA kwenzeka kwiinuclei zeeseli.

Izinto eziphathekayo kwi-biosynthesis yamaqela ahlukeneyo kunye neentlobo ze-RNA yizixhobo ezinamandla: i-ATP, i-GTP, i-CTF kunye ne-TTF. I-Ribonucleic acid ingenziwa ngokubambisana ngokuthatha inxaxheba kwesinye seziqhekeza ezintathu: i-RNA-dependant RNA polymerase, i-polynucleotide-nucleotide-transferase kunye ne-RNA-dependant RNA polymerase. Iyokuqala kwezi zinto ziqulethwe kwinuclei yazo zonke iiseli, nazo zifumaneka kwi-mitochondria. I-RNA ihlanganiswa kwi-DNA matrix phambi kwe-ribonucleoside triphosphates, iMangan ne-Magnesium ions. I-molecule ye-RNA isakhiwe ehambelana nesifanekiso seDNA. Ukuze i-DNA iphinde iphendule kwi-nuclei, r-RNA-, t-RNA-, ne-RNA- kunye ne-RNA-primers zenziwe. Iintathu zokuqala zithunyelwa kwi-cytoplasm, apho zithatha inxaxheba kwi-biosynthesis yeprotheni.

Ukuphindaphinda kweDNA kwenzeka phantse kunye nokuguqulelwa kwe-deoxyribonucleic acid. Ukutshintshwa, kunye nokugcinwa kolwazi oluzuze ilifa lwenziwa ngamanyathelo amabini: ukubhalwa kwephepha kunye nokuguqulelwa. Yintoni i-gene? I-gene iyisunithi yezinto eziphathekayo eziyingxenye ye-molecule ye-deoxyribonucleic acid (i-RNA kwezinye iigciwane). Iqulethwe kuma-chromosomes e-cell nuclei. Ulwazi lwe-Genetic ludluliselwa kwi-DNA kwiRNA kwiprotein. Utshintshi olwenziwa kwi- cell nucleus kwaye luququzelelwe kwi-i-RNA kwiindawo ze-molecule ye-deoxyribonucleic acid. Kufuneka kuthethwe ukuba ulandelelwano lwe-nucleotide lwe-deoxyribonucleic acid "lubhala kwakhona" ngokulandelelana kwe-nucleotide ye-molecule ye-RNA. I-RNA polymerase iqhotyoshelwe kwisiza se-DNA esifanayo, "siyakhupha" i-helix kabini kwaye ikopi ifom ye-deoxyribonucleic acid, ifake i-nucleotides ngokuhambelana nomgaqo wokudibanisa. Njengoko le fragment ishukumisela, i-RNA yokwenziwa kwe-RNA iyahamba isuka kwi-matrix, kwaye i-helix kabini ye-DNA emva kwe-enzyme iyabuyiselwa ngokukhawuleza. Ukuba i-RNA polymerase ifinyelela ekupheleni kwesayithi elikopishiwe, i-RNA isuka kude kumatrix ukuya kwi-karyoplasm, ize iqhubekele kwi-cytoplasm, apho ithatha inxaxheba kwi-biosynthesis yeprotheni.

Ngexesha lokuguqulela, ulandelelwano lwe-nucleotide kwi-molecule ye-RNA liguqulelwa ngokulandelelana kwee-amino acid ezikhoyo kwi-molecule. Le nqubo ivela kwi-cytoplasm, kwaye i-RNA idibanisa kwaye i-polysome yenziwa.