Nucleotide - ke eng see? Sebopeho, sebopeho, palo le tatelano ea nucleotides ka ketane DNA

lintho tsohle tse phelang lefatšeng e entsoe ka lisele tse ngata tse tšehetsang ho hlopha ea mokhatlo o hlophisitsoeng oa bona a bale litsenyehelo tse motheo oa boitsebiso bo liphatseng tsa lefutso. E ntse e le teng, kenngwa tshebetsong le tšoaetsanoang ka metsoako e rarahaneng macromolecular - e acid e nucleic entsoeng ka diyuniti ho monomer - nucleotides. ho ke ke ha khoneha ho feteletsa karolo ea acid nucleic. Botsitso ba dibopeho tsa bona e behilweng ke ea ka tšebetso e tloaelehileng ea phelang, 'me bopengwi efe kapa efe ka ho sebopeho sa tla hona joang kapa joang lebisa liphetoho mokhatlong o hlophisitsoeng oa lisele, mosebetsi oa dithulaganyo fisioloji le solofetsa ea lisele ka kakaretso.

Khopolo ea ho nucleotide le thepa ea eona

E mong le e molek'hule ea DNA kapa RNA e entsoe ka metsoako e nyenyane monomeric - nucleotide. Ka mantsoe a mang, ho nucleotides - moaho diboloko di acid nucleic, sebedisana enzyme le tse ling tse ngata metsoako tsa likokoana-hloko, e leng ee e mahlonoko seleng nakong ea bophelo ba lona.

The thepa ka sehloohong sa dintho tsena tsa bohlokwa kenyeletsa:

• polokelo ya tlhahisoleseding e mabapi le mohaho protheine le mekhoa futsitseng;
• Control fetela ho kgolo le ho ikatisa;
• ho kenya letsoho ha metabolism le tse ling tse ngata dithulaganyo fisioloji ka seleng.

Sebopeho sa nucleotides ho

Ha a bua ka nucleotides, re ka ke ua lula u nahana ka taba tsa bohlokoa tse kang sebopeho bona le sebopeho.

E mong le e nucleotide na le:

• tsoekere masalla;
• nitrogenous botlaaseng;
• phosphate sehlopha kapa masalla ea acid e phosphoric.

Re ka bolela hore nucleotide - e rarahaneng manyolo komponeng. Ho itšetlehile ka ea ho hlophisoa e itseng le ho mofuta oa makalana nitrogenous ka nucleotide pentose sebopeho acid e nucleic arologanyediwa ka paka ya ka:

• acid e deoxyribonucleic kapa DNA;
• acid e ribonucleic, kapa RNA.

Sebopeho acid e nucleic

The nucleic acid e-pentose tsoekere e hlahisa. Ena tsoekere hlano k'habone ka DNA e bitsoa deoxyribose, ka RNA - ribose. E mong le e molek'hule o pentoses liathomo tse hlano k'habone, tse 'nè tsa eo hammoho le athomo oksijene theha reng hlano membered,' me karolo ea bohlano ea sehlopha HO-CH2.

Boemo ba e mong le e athomo k'habone ka molek'hule ea pentose denoted Searabia ho sebediswa makgetlo a ka sehloohong (ya 1c ', 2C', 3C ', 4C', 5C '). Kaha dithulaganyo tsohle bala oa boitsebiso bo liphatseng tsa lefutso le limolek'hule nucleic acid e na le directivity ka tieo, e baloang ba liathomo k'habone le tokisetso ea bona lesale la sebeletsa e le sesupi tataiso nepahetse.

Sehlopha hydroxyl ho oa boraro le ea bohlano liathomo k'habone (le bo3 'ya bo5') khomaretse phosphoric acid e masalla. O etsang qeto hore na lik'hemik'hale tsa DNA le RNA ho sehlopha sa acid.

Pele k'habone athomo (1S ') nitrogenous botlaaseng khomaretse ho tsoekere molek'hule.

Mefuta makalana sebopeho nitrogenous

Nucleotides tsa makalana nitrogenous DNA ba emeloang ke mefuta e mene:

• adenine (A);
• guanine (G);
• cytosine (C);
• thymine (T).

Pele ba babeli ba ho matleng a sehlopha sa purines, ba babeli ho qetela - pyrimidine. Limolek'hule boima purine pyrimidine ke kamehla boima.

Nucleotides RNA makalana nitrogenous se li emetseng:

• adenine (A);
• guanine (G);
• cytosine (C);
• uracil (U).

Uracil hammoho le thymine, e pyrimidine botlaaseng.

Ka lingoliloeng tsa saense 'me hangata ka fumana tse ling tse kgetho nitrogenous bokatlase - mangolo Latin (A, T, C, G, U).

ntlha e khōloanyane le mohaho o lik'hemik'hale tsa purines le pyrimidines.

Pyrimidines, e leng, cytosine, thymine le uracil, ka sebopeho sa emeloang ke tse pedi liathomo naetrojene le liathomo tse 'nè tsa k'habone eaba ba etsa tse tsheletseng membered lesale. Mong le e mong athomo e na le nomoro ea eona ho tloha ho 1 ho 6.

Purines (adenine le guanine) e na le pyrimidine le imidazole kapa heterocycles tse peli. Molek'hule purine makalana emeloang ke liathomo naetrojene tse 'nè le liathomo k'habone tse hlano. E mong le e athomo baloa ho tloha ka 1 ho 9.

La sephetho le motsoako oa nitrogenous botlaaseng le masalla pentose thehoa cytidine. Nucleotide - e komponeng cytidine le sehlopha phosphate.

Sebopeho sa litlamo phosphodiester

Ke habohlokoa ho utloisisa potso ea kamoo ho ka kopana le nucleotides ka ketane polypeptide ho theha e nucleic acid e molek'hule. Sena se etsahala ka lebaka la seo ho thoeng ke litlamo phosphodiester.

Sebelisana tsa nucleotides pedi fana dinucleotide. Sebopeho sa metsoako e ncha e hlaha ke condensation e pakeng tsa phosphate masalla tsa monomer mong le e mong hydroxy pentose phosphodiester tlamo e se hlahile.

Polynucleotide tswakana - khafetsa ho pheta-pheta itsoara joang ka sena (a milione maloa linako). A ketane polynucleotide e hahoa ke eaba ba etsa litlamo phosphodiester pakeng tsa boraro le ea bohlano carbons tsoekere (bo3 'me ya bo5').

Bokana polynucleotide - e rarahaneng hore nka sebaka ha potlakisang tsebetso ea lik'hemik'hale DNA polymerase, eo e fana feela kgolo ketane ho e 'ngoe qetellong (3') le le se nang hydroxy sehlopha.

Sebōpeho sa DNA molek'hule

A DNA molek'hule hammoho le protheine e ka ba ka sehloohong, se mahareng le phahameng sebopeho.

Tatelano ya nucleotides ka ketane DNA e hlalosa ka tsela e ikhethang sebopeho. sebopeho se mahareng Ho thehoa ka lebaka la ho litlamo hydrogen, motheong oa eo ketsahalo e sa beha complementarity molao-motheo. Ka mantsoe a mang, ka tswakana tsa DNA habeli Helix sebetsang sebakeng sa hae kamehla itseng: adenine, thymine tšoana le ea potoloho a mang, guanine - cytosine le sekgoeng. Lipara tsa adenine le thymine kapa guanine le cytosine ba thehoa ke tse peli tsa pele le ka qetellang litlamo hydrogen hlahletsoe nyeoe tse tharo. Joalo komponeng e fana ka o tiileng liketane tlamo e nucleotide le hole lekanang pakeng tsa bona.

Ho tseba tatellano ea nucleotides ka ketane DNA ke molao-motheo oa complementarity ka bontšoa bobeli kapa tlatsetsa.

Sebopeho e phahameng ea DNA e rarahaneng Ho thehoa ka litlamo tse tharo-tlhakore, eo molek'hule etsa hore ho ho feta diseke ee le ea nang le bokhoni kenngoa ka seleng e nyenyane bophahamo ba modumo. Mohlala, E. coli DNA bolelele o moholo ho feta 1 limilimithara, ha bolelele seleng ea - ba ka tlase ho 5 microns.

palo ea nucleotides ka DNA, 'me e ke kamano ea bona ditirisanommogo e ka tlasa puso Chergaffa (nomoro ya makalana purine li kamehla lekanang le palo ya pyrimidine). Sebaka se pakeng tsa nucleotides - e kamehla lekana le 0,34 NM, 'me boima ba' mele ea bona ea limolek'hule.

Sebōpeho sa e RNA molek'hule

RNA e emeloang ke ketane le 'ngoe polynucleotide, thehoa ka litlamo covalent pakeng pentose (ribose tabeng ena) le phosphate moiety. Bolelele e le lintho tse ngata e khutsoanyane DNA. The mefuta e Sebopeho sa makalana nitrogenous ka nucleotide le ho na le ho se tšoane. The RNA pyrimidine botlaaseng thymine sebakeng sa uracil sebediswa. Ho itšetlehile ka hore mesebetsi etsoa ka 'mele, RNA ka' na ba ea mefuta e meraro.

• Ribosomal (rRNA) - tla ka kakaretso na le ho tloha 3000 ho nucleotides 5,000. Ka hlokahala mehaho motsoako ho akarelletsa ho bōptjoa ha setsi mafolofolo ribosomes, le libakeng tsa e mong oa le thulaganyo bohlokoa ka ho fetisisa ka seleng - protheine biosynthesis.
• Transport (tRNA) - e na le karolelano ea tse 75 - 95 nucleotides, o etsa phetiso ho sebaka sa a lakatsa amino acid e polypeptide tswakana ka ribosome. E mong le e mofuta oa tRNA (bonyane 40) e na le tlholeho lona feela e le tatelano ea nucleotides kapa monomers.
• Information (RNAi) - ka nucleotide sebopeho e sa tšoaneng haholo. Phetiso ea boitsebiso bo liphatseng tsa lefutso ho tloha DNA ho ribosomes, sebetsang sebakeng sa hae e le thempleite bakeng sa ho tswakana tsa protheine molek'hule.

Karolo e phethoang ke nucleotides 'meleng

Nucleotides ka seleng phetha palo ya mesebetsi ea bohlokoa:

• ba sebelisoa e le thepa ea mohaho ho na le masakana tsa acid nucleic (nucleotide purine le pyrimidine letoto la lihlooho);
• ameha dithulaganyo tse ngata tshilong ya dijo ka seleng;
• karolo ea ATP - matla ka sehloohong mohloding liseleng;
• ketso e le vectors tsa fokotsa equivalents ka seleng (nad +, NADP +, feshene, FMN);
• ketso e le bioregulators;
• ka ho nkoa e le manģosa bobeli kantle ho sele tswakana kamehla (mohlala, hlomang liahelo ka kapa cGMP).

Nucleotide - e monomer unit trust e bopa ho feta metsoako e rarahaneng - acid nucleic, ntle eo ho fetiswa ha lesedi liphatsa tsa lefutso, polokelo ea sona 'me e bapala. Free nucleotides ke metsoako e ka sehloohong ho akarelletsa le thulaganyo pontšo matla le lisele tse tshehetsang le tshebetsong tlwaelehileng ya phelang eohle.