Sakhiwo DNA yomuntu

Ukuba khona abahlala ndaba ngenxa yokubakhona acid nucleic. F. Miescher lokuqala isehlane lezi izinto kusukela leukocyte nuclei (1869). Kamuva kwafumaniseka ukuthi babe yizinkulungwane wonke amaseli eziphilayo (abantu, izilwane, izitshalo, lamagciwane).

Nucleic acid - Prostatic iqembu nucleoproteins. I hydrolysis we acid nucleic etholwe elisekela nitrogen (i-adenine, ne-cytosine, i-guanine uracil ne thymine), pentoses (deoxyribose, ribose), kanye ne-phosphate acid. Banikezwe Ukwakheka kwamakhemikhali, acid nucleic oluthathwa (DNA) deoxyribonucleic futhi ribonucleic acid (RNA). Isimiso somuntu isakhiwo DNA kuhlanganisa deoxyribose, e-RNA - ribose. Lezi acid kuhluke yamangqamuzana isakhiwo, Ukwakheka nitrogen lezisekelo, yeselula kwasendaweni, futhi yebo, imisebenzi. Biosoedineniya-molecule esakhiwa purine noma pyrimidine base monosaccharides (ribose noma deoxyribose), ngokuthi nucleosides. Isihloko-nucleoside kunqunywa base-nitrogen, okuyinto ezikuyo. Ngakho, i-nucleoside ebandakanya ngaphakathi isakhiwo yayo i-molecule adenine ihambisane libizwa adenosine, ne-thymine - thymidine, uracil - uridine, cytosine - cytidine, i-guanine ne - guanosine. Kuye monosaccharides (pentoses) ayingxenye yezinhlayiya ukuhlukanisa ribonucleosides futhi deoxyribonucleosides.

Human DNA - chemical isisekelo zezakhi zofuzo, lapho zofuzo ulwazi i umzimba okungukuthi kanzulu. Kuhunyushelwe ikakhulukazi le nuclei amaseli, mhlawumbe kuma-chromosome. Phakathi hydrolysis ka-nucleotide DNA akhiwa: dezoksiadenilovaya (A) dezoksiguanilovaya (T) dezoksitsitidilovaya (U) kanye thymidylic (T) acid. Ngezinye izikhathi ama-nucleotide kutholwa lichaza ekwakheni izinto eziningi ezincane nezinye amagama ahlobene of purines futhi pyrimidines - base ezincane: 5-oksimetiltsitozin (e bacteriophages), 5-methylcytosine (e izicubu thymus), kanye nabanye. Nucleotide axhunyiwe besifunda polynucleotide (DNA) umoya-mpilo amabhuloho akhiwa hydroxyl ngenxa - amasalela phosphate acid elilodwa nucleotide futhi iqembu hydroxyl ngesikhathi carbon wesithathu amasalela deoxyribose nucleotide athomu yesibili.

I nucleotide ukulandelana yokuhlala DNA ekuhloleni kwabantu by • Ukutshengisa ukulangazelela nokuthatheka (Engl seguence -. Lolu cwaningo wokulandelana). Ngenxa yale njongo, idivayisi sequencer ukuthi kusekelwe ikhompyutha ukuhlaziywa nucleotide ukulandelana isethi nokubekwa (kufika ku amayunithi eziyikhulu).

Isibalo ama-nucleotide e molecule e-DNA bangabantu 25 000 - 35 000 noma ngaphezulu, futhi isisindo yamangqamuzana -. Kusuka eziyizigidi ezimbalwa ukuze 2-5 bhiliyoni molecule e-DNA 'simbone' e-microscope-electron. Inani eliphelele izinhlobo ezine nucleotide (A, G C no T) e molecule e-DNA Lokudabuka ezahlukene ziyehluka amabanga ububanzi.

Isakhiwo eyinhloko-DNA

Crick futhi D. Watson ngo-1953, ukusungula ukuthi deoxyribonucleic acid molecule a double Helix polynucleotide ngamaketanga, ezingqubuzanayo ezaziyaluzisa azungeze axis awo. Kuvunguza sifana ezitebhisini Kuvunguza, okuyinto wesitimela kwakhiwa deoxyribose izinsalela oxhumene izibopho phosphorus-ether ohlobo 3 - 5, kanye izinyathelo - nitrogen elisekela. Adenine ixhunyiwe nge-hydrogen izibopho ihlangane ne-thymine, i-guanine ne - ne-cytosine. Ukucushwa deoxyribonucleic acid angase onomfutho futhi welulela. Lona-DNA isakhiwo yesibili. Ezinye bacteriophages wathola single- DNA. Se-deoxyribonucleic acid-molecule isici isakhiwo nemayunivesithi, ezakhiwe sihlangane double balahleke namafomu isiyingi DNA superspiralizirovannyh kumiswa okwalandela spiralizirovannyh futhi izakhiwo okuyinto.