Main qhov chaw ntawm cov protein biosynthesis. Cov kauj ruam uas muaj protein ntau biosynthesis

Protein synthesis - ib tug tseem ceeb heev txoj kev. Nws yog nws leej twg yuav pab peb lub cev kom loj hlob thiab tsim. Nws muaj ntau yam cell lug. Tom qab tag nrho, mus pib to taub tias peb yuav mus ua ke.

Uas protein yog tsim nyog los tsim thaum lub caij - nws yog lub luag hauj lwm rau cov enzymes. Lawv tau txais Pib ntsais koj teeb ntawm lub hlwb ntawm cov yam tseem ceeb ntawm ib tug protein tom qab uas nws pib synthesis.

Nyob qhov twg lub protein synthesis

Nyob rau hauv txhua lub tawb ntsiab qhov chaw protein biosynthesis - ribosome. Nws yog ib tug loj macromolecule nrog ib tug complex asymmetrical qauv. Nws muaj tub txib RNA (ribonucleic acid) thiab proteins. Ribosomes yuav tsum tau nyob nyias. Tiam sis ntau tshaj feem ntau lawv cov chav nrog tus EPS, uas tswj lub tom ntej sorting thiab thauj proteins. Yog hais tias lub endoplasmic reticulum sit ribosome, nws yog hu ua ntxhib EPS. Thaum translation tshwm sim sib rau ib tug matrix yuav tsiv mus nyob ob peb ribosomes. Lawv yuav tom qab txhua lwm yam thiab tsis cuam tshuam nrog rau lwm cov organelles.

Yuav ua li cas yog tsim nyog rau cov protein ntau synthesis

Rau cov chav kawm ntawm lub txheej txheem nws yog tsim nyog tias tag nrho cov loj Cheebtsam ntawm cov protein-synthesizing system nyob rau hauv qhov chaw:

1. Qhov kev pab cuam, uas qhia txog qhov kev txiav txim ntawm cov amino acid residues nyob rau hauv cov saw hlau, uas yog ib qho mRNA uas yuav hloov cov ntaub ntawv no los ntawm cov DNA mus rau lub ribosomes.
2. Amino acid ntaub ntawv los ntawm kev uas mus tsim lub tshiab qauv.
3. tRNA, uas yuav xa txhua amino acid mus rau lub ribosome, yuav muab ib feem nyob rau hauv lub deciphering ntawm lub caj code.
4. Aminoacyl-tRNA synthetase.
5. Ribosomes - yog qhov tseem ceeb qhov chaw ntawm cov protein biosynthesis.
6. Zog.
7. Magnesium ions.
8. Protein yam (rau txhua theem ntawm koj tus kheej).

Tam sim no saib txhua ntawm lawv nyob rau hauv kev nthuav dav thiab kawm tau li cas los tsim proteins. biosynthesis mechanism yog heev nthuav, tag nrho cov Cheebtsam yog cov tsis tshua ntseeg nkaws.

synthesis kev pab cuam, cov kev tshawb fawb matrix

Tag nrho cov ntaub ntawv hais txog raws nraim uas cov nqaijrog yuav tsim peb lub cev yog muaj nyob rau hauv lub DNA. Deoxyribonucleic acid yog siv rau cia ntawm kev tshuaj ntsuam genetic ntaub ntawv. Nws yog securely tau ntim rau hauv chromosomes thiab yog nyob rau hauv lub cell nucleus (nyob rau hauv cov ntaub ntawv ntawm eukaryotes) los yog floats nyob rau hauv lub cytoplasm (nyob rau hauv prokaryotes).

Tom qab kev tshawb fawb ntawm DNA thiab kev tshuaj ntsuam genetic paub txog nws lub luag hauj lwm, nws ua qhov tseeb hais tias nws tsis yog ib tug qauv rau neeg txhais lus. Lub tswvyim coj mus rau lub hypothesis hais tias cov protein synthesis txuam RNA. Lub zaum txiav txim siab tias nws yuav tsum nrog mloog, mus rau cov hloov ntaub ntawv los ntawm DNA mus rau lub ribosomes, pab raws li ib tug template.

Nyob rau tib lub sij hawm, lawv qhib lub ribosome RNA ntawm lawv ib thooj ntawm cellular RNA. Mus xyuas seb nws yog ib tug qauv rau cov protein ntau synthesis, IB Belozersky thiab A. S. Spirin nyob rau hauv 1956-1957. Peb ua ib tug sib piv tsom xam ntawm lub qauv ntawm nucleic acids nyob rau hauv ib tug loj tus naj npawb ntawm microorganisms.

Nws twb assumed tias yog hais tias lub tswv yim ntawm ib tug "DNA-rRNA-protein" tswvyim yog muaj tseeb, ces cov muaj pes tsawg leeg ntawm tag nrho cov RNA yuav hloov raws li zoo raws li DNA. Tab sis txawm lub loj loj sib txawv nyob rau hauv lub deoxyribonucleic acid nyob rau hauv hom sib txawv, cov muaj pes tsawg leeg ntawm tag nrho cov ribonucleic acids yog zoo xws li cov nyob rau hauv tag nrho cov nais maum kuaj kab mob. Li no, zaum tau xaus lus hais tias lub ntsiab cellular RNA (ie, ribosomal) - qhov no yog tsis yog ib tug ncaj qha intermediary ntawm cov cab kuj ntawm kev tshuaj ntsuam genetic ntaub ntawv thiab protein.

Qhib mRNA

Tom qab ntawd nws twb pom hais tias ib tug me me feem ntawm RNA repeats ntawm DNA thiab yuav ua ib tug intermediary. Nyob rau hauv 1956 los ntawm E. thiab F. Volkin Astrachan RNA synthesis yog kawm nyob rau hauv cov kab mob, uas muaj tus kab mob nrog bacteriophage T2. Tom qab nws nkag mus rau hauv lub cell, nws yog hloov mus rau lub synthesis ntawm phage proteins. Lub ib thooj ntawm cov RNA twb tsis tau hloov. Txawm li cas los, lub hlwb pib synthesis ntawm ib tug me me feem ntawm metabolically tsis ruaj tsis khov RNA, ib theem zuj zus ntawm nucleotides nyob rau hauv uas muaj pes tsawg leeg yog zoo li tus phage DNA.

Nyob rau hauv 1961, qhov no yog me me feem ntawm RNA yog cais los ntawm cov yuag tag nrho RNA. Ntawv pov thawj ntawm nws lag luam muaj nuj nqi twb tau los ntawm lub thwmsim. Tom qab kab mob nrog phage T4 hlwb tsim tshiab mRNA. Nws mus nrog cov laus tswv tsev lub ribosomes (lub ribosome tom qab tshiab kab mob yog tsis kuaj), uas pib lub phage tsim proteins. Qhov no "DNA zoo li RNA" yog complementary rau ib qho ntawm lub chains ntawm lub phage DNA.

Nyob rau hauv 1961, F. Yakhauj thiab J. Monod qhia lub tswv yim hais tias qhov no RNA yog ntaub ntawv los ntawm cov noob mus rau lub ribosome thiab yog ib tug qauv rau cov tshwm sim los muaj kev kho ntawm cov amino acids thaum lub sij hawm protein synthesis.

Cov kev hloov ntawm cov ntaub ntawv los ntawm qhov chaw ntawm cov protein synthesis muab kev koom tes nyob rau hauv mRNA. Tus txheej txheem ntawm kev nyeem ntawv cov ntaub ntawv los ntawm DNA thiab RNA template creation hu ua transcription. RNA tom qab nws yog raug mus rau ib tug xov tooj ntawm cov ntxiv hloov, qhov no yog hu ua "kev". Nyob rau hauv tej qhov chaw muaj peev xwm yuav txiav tawm ntawm nws thaum lub sij hawm tus tub txib ribonucleic acid. Tom ntej no mRNA mus rau ib tug ribosome.

Tsev blocks ntawm cov nqaijrog: amino acids

Nyob rau hauv tag nrho muaj yog 20 cov amino acids, ib txhia ntawm lawv yog cov tseem ceeb, uas yog, lub cev tsis tau ke lawv. Yog hais tias tej acid nyob rau hauv lub cell yog tsis txaus, nws yuav qeeb los yog txawm tshaj tawm hauv xov ib tug tag nrho cov nres cov txheej txheem. Lub xub ntiag ntawm txhua amino acid nyob rau hauv txaus kom muaj nuj nqis - lub ntsiab yuav tsum tau kom zoo zoo dhau protein biosynthesis.

General ntaub ntawv rau amino acids, zaum muaj nyob rau hauv lub XIX caug xyoo. glycine, leucine, thiab - nyob rau tib lub sij hawm, nyob rau hauv 1820, thawj ob amino acids tau cais.

Cov kab sab ntawm cov monomers nyob rau hauv lub protein (lub thiaj-hu ua thawj qauv) kiag li txiav txim raws li nram no theem ntawm lub koom haum, thiab yog li ntawd nws lub cev thiab tshuaj zog.

amino acids Tsheb thauj mus los: tRNA thiab ib tug ib tug-tRNA synthetase

Tab sis amino acids ib leeg yuav ua tsis tau mus rau hauv lub protein saw. Nyob rau hauv kev txiav txim rau lawv kom tau mus rau lub ntsiab qhov chaw ntawm cov protein synthesis, RNA yuav tsum tau thauj.

Txhua aa-tRNA synthetase paub xwb nws amino acid thiab tRNA tsuas yog hais tias uas nws yog tsim nyog los muab. Nws hloov tawm hais tias nyob rau hauv no tsev neeg ntawm enzymes muaj xws li 20 ntau ntau yam ntawm synthetases. Nws tsuas tseem hais tias cov amino acids uas txuas mus rau tRNA hais tias, precisely ntau, rau nws cov hydroxyl acceptor "Tsov tus tw". Txhua acid yuav tsum sib haum mus rau nws hloov lwm lub tsev RNA. Qhov no yog ua raws li los ntawm cov aminoacyl-tRNA synthetase. Nws tsuas tsis piv nrog qhov tseeb amino acid thauj, nws kuj regulates lub tsim tshuaj tiv thaiv ntawm lub ester daim ntawv cog lus.

Tom qab kev vam meej Symptoms cov tshuaj tiv thaiv tRNA mus yuav tus site ntawm protein synthesis. Thaum no xaus txoj kev npaj dab thiab cov tshaj tawm hauv xov pib. Lub ntsiab theem ntawm cov protein biosynthesis:

• pib;
• elongation;
• txiav.

synthesis kauj ruam: pib

Yuav ua li cas puas muaj tus protein biosynthesis thiab nws cov kev cai? Zaum tau sim mus nrhiav tau tawm rau ib lub sij hawm ntev. Heev heev hypotheses muab rau pem hauv ntej, tab sis nws ua ntau niaj hnub khoom, lub zoo dua peb yuav tsum to taub lub hauv paus ntsiab lus ntawm txhais lus.

Ribosome - tus thawj xib fwb qhov chaw ntawm cov protein biosynthesis - mRNA pib nyeem ntawv los ntawm tus taw tes uas nws pib ib feem encoding ib polypeptide saw. Qhov no yog nyob rau ntawm ib tug deb ntawm pib ntawm tus tub txib RNA. Lub ribosome yuav tsum nrhiav tau ib tug taw tes rau lub mRNA los ntawm uas pib nyeem ntawv, thiab xa mus rau nws.

Pib - ib tug txheej ntawm cov txheej xwm uas muab pib ntawm lub tawm. Nws yuav cov nqaijrog (pib yam), thiab ib tug tshwj xeeb initiator tRNA initiator codon. Rau ntawm no theem, me me subunit ribosomal protein-ua ke yuav pib. Lawv yuav tsis pub hu rau nrog ib tug loj subunit. Tab sis muaj cai mus txuas rau lub initiator tRNA thiab GTP.

Ces, qhov no complex "tso" nyob rau mRNA, nws yog nyob rau hauv lub feem uas yog paub los ntawm ib yam ntawm pib yam. Uas tsis tsis tau yuav, thiab lub ribosome pib nws cov lus rau tus tub txib RNA, nyeem ntawv nws codons.

Thaum lub complex los txog rau lub pib codon (Aug), subunit nres zog thiab nrog rau cov kev pab los ntawm ib tug txawv protein yam khi rau cov loj ribosomal subunit.

synthesis kauj ruam: elongation

Nyeem mRNA synthesis yuav tshwm sim los muaj polypeptide saw ntawm cov protein. Nws yog los ntawm kev ntxiv ib amino acid residues yog nyob rau hauv succession mus rau lub molecule nyob rau hauv kev tsim kho.

Txhua tshiab amino acid residue yog ntxiv rau cov carboxyl terminus ntawm lub peptide, lub C-terminus yog loj hlob.

synthesis kauj ruam: txiav

Thaum lub ribosome nce mus txog ib tug nres codon tub txib RNA, lub synthesis ntawm polypeptide chains haujlwm. Nyob rau hauv nws lub xub ntiag, ib organelle yuav tsis txais tej tRNA. Es tsis txhob, qhov ua rau ntawm kev txiav yam nkag mus. Lawv tso lub tiav lawm protein los ntawm stalled ribosomes.

Tom qab txiav ntawm txhais lus, lub ribosome yuav yog mus rau lub mRNA, los yog txuas ntxiv mus xaub raws nws, tsis broadcasting.

Lub rooj sib tham ntawm lub ribosome nrog tus tshiab initiator codon (nyob rau tib lub Circuit Court thaum lub sij hawm lub continuation ntawm lub zog, los yog nyob rau hauv lub tshiab mRNA) yuav ua tau kom ib tug tshiab pib.

Thaum tiav lawm cov molecule yoojyim tus thawj xib fwb qhov chaw ntawm cov protein biosynthesis, nws yog cim thiab xa mus rau lo lus uas peb. Yuav ua li cas zog nws yuav ua tau, nyob ntawm seb nws cov qauv.

txheej txheem tswj

Nyob ntawm seb koj xav tau kev pab, lub cell yuav nws tus kheej tswj cov tshaj tawm hauv xov. Cov kev cai ntawm protein biosynthesis - ib tug tseem ceeb heev muaj nuj nqi. Nws yuav ua tau nyob rau hauv ntau txoj kev.

Yog hais tias lub cell tsis xav tau ib co zoo ntawm kev twb kev txuas, nws yuav nres lub biosynthesis ntawm RNA - protein biosynthesis kuj tsum tshwm sim. Tom qab tag nrho, tag nrho cov txheej txheem yuav tsis pib tsis muaj ib tug template. Thiab cov laus mRNA lwj sai heev.

Yog lwm kev cai ntawm protein biosynthesis: cell tsim enzymes uas cuam tshuam nrog cov khiav ntawm lub pib theem. Lawv cuam tshuam nrog rau cov kev tshaj tawm, txawm yog hais tias tus matrix rau kev nyeem ntawv yog muaj.

Qhov thib ob hom yog yuav tsum tau nyob rau hauv lub rooj plaub uas lub protein synthesis mus kaw lawm txoj cai tam sim no. Tus thawj txoj kev yuav cov continuation ntawm sluggish tawm tej lub sij hawm tom qab txiav ntawm mRNA synthesis.

Lub cell yog ib tug heev system nyob rau hauv uas txhua yam yog khaws cia nyob rau hauv qhov nqi koj tshuav ntawv thiab cov tus khiav ntawm txhua molecule. Nws yog ib qho tseem ceeb kom paub tias cov hauv paus ntsiab lus ntawm txhua txoj kev nyob rau hauv lub cell. Yog li ntawd peb yuav to taub zoo dua dab tsi tshwm sim nyob rau hauv cov ntaub so ntswg thiab lub cev raws li ib tug tag nrho.