Yuav ua li cas yog polysomes. Tus qauv ntawm tsab cai prokaryotes thiab eukaryotes

Protein synthesis - nws yog ib tug tseem ceeb heev lom txheej txheem uas tshwm sim nyob rau hauv lub hlwb ntawm tej kab mob. Cov nqaijrog yog lub ntsiab hauv chav kawm ntawv ntawm cov organic tshuaj hlwb, ua ib tug ntau ntawm cov kev khiav dej num, pib thiab xaus nrog ib tug tiv thaiv enzyme. Yuav ua li cas yog polysomes? Raws li cov qauv no yog siv nyob rau hauv protein synthesis?

Yuav ua li cas yog polysomes

Nyob rau hauv lub hlwb ntawm eukaryotes thiab prokaryotes yog losis tswvyim dabtsi lug ntawm cov ribosome. Qhov no me me corpuscles, muaj raws ntawm ob subunits thiab cov kev ua ntawm kev ua tau zoo protein synthesis nyob rau hauv tus neeg txhais lus txheej txheem. Ribosome - ib tug uas tsis yog-daim nyias nyias qauv.

Polysomes - ib tug tsim muaj ob peb ribosomes. Lawv sib txuas lus nrog txhua lwm yam nyob rau ntawm lub matrix los yog cov tub txib RNA. Ob peb ribosomes, xws li cov hlaws dai, yog muab tso rau no molecule ua nyob rau hauv ib tug nqaij daim tawv qauv - polysomes.

Polysomes hlwb yog feeb meej nyob qhov twg yuav tsum tau ceev ceev synthesis ntawm loj nyiaj ntawm cov proteins. Qhov no yog lub ntsiab lom luag hauj lwm ntawm cov chaw.

Tus qauv ntawm lub ribosome

T. k. Polis tsim ob peb yam ribosomes, koj yuav tsum xav txog cov qauv ntawm cov caij nyoog kawg no.

Tej cell ribosome muaj ob subunits, loj thiab me me. Nruab nrab ntawm lawv yog tsim ib tug me me kis kab uas hla haum rau precision nyob rau hauv lub mRNA molecule uas yuav tsum muaj.

Ribosomes muaj txoj nucleoprotein ceg, piv txwv li. K. Ib feem ntawm ob leeg me me thiab cov loj loj subunit ribosomal RNA molecules xws li cov nqaijrog thiab. Cov nqaijrog ua cov kev ua ntawm lub cev, thiab RNA uas muaj ribozyme (fermentative) ua si, uas yog siv nyob rau hauv cov neeg txhais lus txheej txheem.

Txawv ntawm prokaryotic thiab eukaryotic ribosomes

. Txij li thaum lub prokaryotes thiab eukaryotes - lawv yog cov ob tug sib txawv pab pawg ntawm cov kab mob, lawv muaj sib txawv nyob rau hauv lub ribosomes, thiab yog li ntawd txoj cai, ib yam nkaus thiab.

Nyob rau hauv prokaryotes, lub cytoplasm yog ib tug loj npaum li cas ntawm 70s ribosomes (S - sedimentation yog qhov, uas qhia tus nqi ntawm deposition ntawm hais nyob rau hauv ib tug centrifuge). Lawv tsim los ntawm loj subunit 50s thiab 30s me me subunit. Tus qauv ntawm lub loj subunit nyob rau hauv prokaryotes muaj xws li 5 thiab 23S RNA. Nyob rau hauv lem, tus me subunit 16s RNA yog tsim.

Nyob rau hauv cov kab mob hlwb tsim ib tug ntau ntawm polysomes. Qhov no yog vim lub fact tias lawv muaj lub protein synthesis txheej txheem yog heev ceev ceev: lub tshaj tawm hauv xov pib ua ntej thaum xaus ntawm lub transcription txheej txheem. Tib yam vim li, lub concentration ntawm ribosomes nyob rau hauv lub cell yog qhov loj tshaj plaws nyob ze ntawm lub nucleoid.

Nyob rau hauv eukaryotes, muaj cov sib txawv nyob rau hauv qhov tseem ceeb ntawm cov qhov ntsiab ntawm lub ribosome sedimentation. Rau nws, tus nqi yog 80 rau lub tsev loj thiab me me subunits - 60 thiab 40 feem. Raws li ib feem ntawm lub loj subunit twb cais 5, 28S thiab 5,8S RNA, thiab me me - 18S RNA.

Thiab nyob rau hauv prokaryotes thiab eukaryotes polysomes leeb tus txheej txheem ntawm cov protein synthesis. Qhov no yog qho tseem ceeb heev thaum koj xav tau ceev ceev tsim ntawm cov ntawv luam ntawm cov protein molecules. Lub siab tus nqi ntawm synthesis tshwj xeeb cov yam ntxwv rau cov kab mob, xws li. K. cov tub txib RNA lawv muaj rau ib tug luv luv lub sij hawm, thiab thaum lub sij hawm no yuav luv los ua ke ntau li ntau ntawm cov protein molecules. Hais tias yog dab tsi polysomes nyob rau hauv biology.

Neeg txhais lus txheej txheem - lub ntsiab muaj nuj nqi ntawm polysomes

Thaum lub sij hawm translation tsim thawj qauv ntawm cov protein molecule. Muaj peb kauj ruam ntawm lub synthesis ntawm polypeptides: pib, elongation thiab txiav.

1. Pib txhais lus. MRNA molecule yuav tsum tau txuas mus rau lub 16s RNA ntawm lub hauv paus ntsiab lus ntawm complementarity. Rau lub hom phiaj no yog ib tug tshwj xeeb ib theem zuj zus uas prokaryotes hu ua ribosomsvyazyvayuschim site thiab eukaryotes - capped. Yog li ntawd, cov tub txib RNA yog txuas mus rau lub me me subunit ntawm lub ribosome.

2. elongation. Qhov no yuav tsis nyob ntev yog tsiag ntawv los ntawm buildup ntawm lub polypeptide saw. Tsheb thauj mus los RNA nqa mus rau lub ribosome amino acids, uas yog kev cob cog rua rau hauv Circuit Court tsim los ntawm peptide bonds. Yog li, protein synthesis yuav siv sij hawm qhov chaw kom txog rau thaum lub caij thaum nws hits ib ribosome nres codon.

3. txiav. Thaum nws tau mus txog lub tsheb codon ntawm cov protein synthesis yog haujlwm. ib tug tshiab khiv tsim polypeptide los ntawm cov ribosome ntog molecule los ntawm ib tug tshwj xeeb stroke, thiab ces kis tau tsim ntawm theem nrab, tertiary los yog quaternary qauv.

Ribosome profiling - cov qauv ntawm cov kawm ribosome

Yog xav paub dab tsi polysomes, koj yuav tsum xaiv cov qauv ntawm cov hlwb ntawm lub cev. Qhov yooj yim txoj kev uas yuav ua kev tshawb fawb rau prokaryotic hlwb. Ribosomal profiling yuav cov nram qab no cov kauj ruam:

1. Cov kev puas ntsoog ntawm lub prokaryotic cell. Nws yog ib qho tseem ceeb tias cov kev puas tsuaj yuav tsum tau nqa tawm los ntawm cov neeg kho tshuab txhais tau tias, piv txwv li. A. Tshuaj yuav ua kev puas lub ribosomes lawv tus kheej.

2. Cov cleavage ntawm RNA, uas yog tsis ribosomal.

3. Cov ntsiab cai tib yam yog nqa tshem ruaj polypeptides uas tsis yog ib feem ntawm cov qauv.

4. Rov qab transcription ntawm ribosomal RNA cais.

5. Sekvernirovanie tau DNA.

xaus

Polysomes - ib tug qauv uas yog tsim nyob rau ntawm ob peb ribosomes. Nws lub hom phiaj yog rau accelerate lub synthesis ntawm proteins. Cov lug muaj nyob hauv hlwb ntawm prokaryotes thiab eukaryotes, tiam sis lawv yog cov yam ntxwv ntawm lub hlwb ntawm tej kab mob. Hais tias yog dab tsi polysomes.