Protein synthesis nyob rau hauv lub cell, ib theem zuj zus ntawm biosynthetic dab. Synthesis ntawm cov nqaijrog nyob ribosomes.

Lub neej yog ib tug txheej txheem ntawm cov hav zoov uas muaj protein ntau molecules. Qhov ntawd yog yuav ua li cas nws yog qhia nyob rau hauv ntau yam ntawm cov zaum uas ntseeg tau hais tias lub protein yog lub hauv paus ntawm tag nrho lub neej. Cov nqe lus yog kiag li lawm, vim hais tias nyob rau hauv cov tshuaj nyob rau hauv lub cell tus loj tshaj xov tooj ntawm yooj yim zog. Tag nrho lwm cov organic tebchaw ua si ib lub luag hauj lwm ntawm lub zog substrates, thiab lub zog yuav tsum tau ntxiv rau cov synthesis ntawm cov protein molecules.

Lub cev muaj peev xwm los ua ke protein

Tsis yog txhua txhua tus uas twb muaj tus kab mob no yuav tau mus nqa tawm lub synthesis ntawm cov nqaijrog nyob rau hauv lub cell. Kab mob thiab tej yam kab mob no tsis tsim cov nqaijrog, thiab yog li ntawd yog cab muab cov yam tshuaj yeeb dej caw los ntawm tus tswv tsev cell. Lwm yam kab mob, xws li prokaryotic hlwb, yuav tau coj los ua ke proteins. Tag nrho cov tib neeg lub hlwb, tsiaj txhu, nroj tsuag, fungi, yuav luag tag nrho cov kab mob thiab protists nyob vim lub peev xwm ntawm cov protein biosynthesis. Qhov no yuav tsum rau qhov kev siv ntawm cov qauv-txoj kev, kev tiv thaiv, receptor, thauj thiab lwm yam kev khiav dej num.

-Stage yam ntxwv protein biosynthesis

Tus qauv ntawm cov protein yog kho nyob rau hauv ib tug nucleic acid (DNA los yog RNA) raws li ib tug codon. Qhov no yog qhov raws roj ntsha cov ntaub ntawv uas yog ua si txhua txhua lub sij hawm lub cell yuav tsum tau ib tug tshiab protein substance. Pib biosynthesis yog cov kis ntawm cov ntaub ntawv mus rau lub nucleus ntawm qhov yuav tsum tau coj los ua ke ib tug tshiab protein muaj zog twb teem.

Nyob rau hauv cov lus teb rau qhov no dispiralized feem ntawm lub nucleic acid, nyob rau nws cov qauv yog coded. Qhov no qhov chaw yog duplicated tub txib RNA thiab pauv mus rau lub ribosome. Lawv yog cov luag hauj lwm rau qhov kev siv ntawm cov polypeptide saw rau lub hauv paus ntawm lub matrix - tub txib RNA. Luv luv tag nrho biosynthetic kauj ruam yog raws li nram no:

• transcription (DNA doubling kauj ruam feem nrog lub encoded protein qauv);
• ua (kauj ruam ntawm txoj kev tub txib RNA);
• translation (protein synthesis nyob rau hauv ib lub cell rau lub hauv paus ntawm cov tub txib RNA);
• posttranslational kev hloov kho ( "maturation" ntawm lub polypeptide, tsim ntawm nws cov peb-dimensional qauv).

Transcription ntawm nucleic acid

Tag nrho cov cell protein synthesis nyob rau hauv ribosome ua, thiab cov ntaub ntawv hais txog molecules muaj nyob rau hauv ib tug nucleic acid (RNA los yog DNA). Nws yog nyob rau hauv lub noob: txhua noob - ib lub protein. Noob incorporated ntaub ntawv hais txog cov amino acid ib theem zuj zus ntawm ib tug tshiab protein. Nyob rau hauv cov ntaub ntawv ntawm qhov kev tshem tawm ntawm DNA kev tshuaj ntsuam genetic code yog ua raws li nram no:

• Nws pib lub liberation ntawm lub nucleic acid feem ntawm histone tshwm sim despiralization;
• DNA polymerase doubles tus DNA feem nyob rau hauv uas lub noob ntawm cov protein yog muab;
• lub ob npaug feem yog ib tug tub txib RNA precursor, uas yog ua los ntawm enzymes rau tshem tawm uas tsis yog-coding inserts (nyob rau hauv lub hauv paus ntawd ua lub synthesis ntawm cov mRNA).

Raws li proinformatsionnoy RNA yog tsim mRNA. Nws yog ib tug twb tau matrix, ces protein synthesis nyob rau hauv lub cell tshwm sim nyob rau hauv ribosomes (nyob rau hauv lub ntxhib endoplasmic reticulum).

Ribosomal protein synthesis

Cov tub txib RNA muaj ob xaus, uas yog ua tawm raws li 3`- 5`. Nyeem Ntawv thiab protein synthesis rau ribosomes nrog 5`kontsa pib thiab tseem kom txog thaum lub intron - feem uas tsis encode ib yam ntawm cov amino acids. Nws yog raws li nram no:

• tub txib RNA "strung" nyob rau ribosome, koom nrog cov thawj amino acid;
• ribosome tsiv raws mRNA mus rau ib tug tib codon;
• Nws muab cov kev kawm hloov lwm lub tsev RNA (mRNA codon encoded cov ntaub ntawv) ntawm ib tug alpha-amino acid;
• amino acid yog txuas mus rau ib tug pib amino acid tsim tau ib dipeptide;
• mRNA ces txav dua los ntawm ib tug codon, ib tug tais thiab ib tug alpha-amino acid yog txuas mus rau ib tug zuj zus peptide saw.

Sai li sai tau raws li lub ribosome nce mus txog lub intron (non-coding insert), cov tub txib RNA tsuas tsiv rau. Ces, raws li cov advancement ntawm cov tub txib RNA, ribosome nce mus txog dua exon - seem, lub nucleotide ib theem zuj zus ntawm uas raws li ib tug kev amino acid.

Los ntawm no taw tes pib dua protein pub ntxiv tshaj monomers rau ib cov saw. Tus txheej txheem ntxiv kom txog rau thaum qhov tshwm sim ntawm lwm intron los yog kom txog thaum lub tsheb codon. Xeem polypeptide saw synthesis terminates, whereupon cov thawj cov protein yog suav ua kom tiav thiab postsynthetic theem pib (posttranslational) kev hloov kho ntawm lub molecule.

post-Translational kev hloov kho

Tom qab translation, protein synthesis tshwm sim nyob rau hauv tso tsheb hlau luam du endoplasmic reticulum. Cov yav tas muaj ib tug me me npaum li cas ntawm ribosomes. Nyob rau hauv ib co hlwb lawv tej zaum yuav tsis tuaj kawm ntawv nyob rau hauv lub Res. Tej chaw yuav tsum tsim ib tug thawj theem nrab, los yog tertiary twb ces, yog xaiv, lub quaternary qauv.

Tag nrho cov cell protein synthesis tshwm sim nyob rau hauv ib tug lossis loj npaum li cas ntawm expenditure ntawm lub zog ntawm ATP. Vim hais tias tag nrho cov lwm yam lom dab yuav tsum tau mus txhawb protein biosynthesis. Nyob rau hauv tas li ntawd, ib co ntawm cov zog yuav tsum tau mus thauj cov nqaijrog nyob rau hauv lub cell los ntawm active thauj.

Muaj ntau ntawm cov proteins uas kis los ntawm ib tug cell mus rau lwm qhov chaw rau cov kev hloov kho. Nyob rau hauv kev, post-Translational protein synthesis tshwm sim nyob rau hauv lub Golgi complex, uas koom carbohydrate los yog lipid sau polypeptide tej qauv.