KumiswaIsayensi

Imisebenzi nucleolar kuseli lokho? I nucleolus: lokuphatselene nesakhiwo nemsebenti

Iseli lisisakhiwo eziphilayo emhlabeni, futhi eziyinkimbinkimbi zamakhemikhali inhlangano izakhiwo ngokuthi organelles. Lezi zihlanganisa i-nucleus, isakhiwo kanye nemisebenzi esizokhuluma uhlole lesi sihloko.

Izici nuclei eukaryotic

amaseli Nucleated ukubunjwa yayo iqukethe organelles non-ulwelwesi laphetha, mkhulu kunokhalo karyoplasm wabiza nucleolus noma nucleoli. Zitholakale lapho ekhulwini le-19. Manje nucleoli ngokwanele wafunda ngokusebenzisa ama-electron microscopy. Cishe kuze 50s umsebenzi nucleolar kwekhulu lama-20 ungazange sezihlonziwe futhi ososayensi kubhekwe lokhu organelle, kunalokho, njengoba agcina izinto ezisele esetshenziswa ngesikhathi mitosis.

Ucwaningo lwamuva isungule ukuthi organoid kuhlanganisa elimbudumbudu imvelo nucleoprotein. Ngaphezu kwalokho, ucwaningo kwamakhemikhali waqinisekisa ukuthi organelle yakhiwa inqwaba amaprotheni. Lokho babangela ukuminyana yaso ephezulu. Ngaphezu kwalokho proteids, nucleoli ekhona Ukwakheka esincane RNA ne-DNA.

iseli umjikelezo

Kuyathakazelisa ukuthi kuyi-ukuphila kwengqamuzana, esakhiwa inkathi yokuphumula (interphase) nokuhlukanisa (meiosis - wobulili, mitosis - le cell ukuphathwa kwabathintwayo), nucleoli egcinwe njalo. Ngakho, kuyi-nucleus interphase ne nucleolus, okuyinto ukusebenza - ukulondolozwa lwezakhi zofuzo kanye ukwakheka organelles amaprotheni-Kuhlanganisa abakhona ngempela. Ekuqaleni cell division, okungukuthi prophase, ayanyamalala uphinde eyakheke kuphela ekupheleni telophase, egcinelwe yezinyoni kuze division elilandelayo noma apoptosis - ukubhujiswa kwalo.

umhleli nucleolus

Esikhathini 30s kwekhulu elidlule, ososayensi batholé ukuthi ukwakheka nucleoli ilawulwa ezigabeni ezithile wama-chromosomes ezithile. Ziqukethe ufuzo, okuyinto ukugcina ulwazi ngalokho isakhiwo begodu bobani nemisebenzi nucleolus kuseli. Kukhona ukuhlanganisa emkhatsini ngobungako umhleli nucleolar futhi organelles ngokwabo. Ngokwesibonelo, Afrika clawed frog iqukethe e yayo chromosome karyotype ezimbili nucleolus futhi ngaleyo ndlela ku-nuclei lamaseli ukuphathwa kwabathintwayo kuba nucleoli ezimbili.

Njengoba imisebenzi nucleolus kanye phambi kwaso Ihlobene ngokuseduze cell division kanye kumiswa ribosomes, le organelles ngokwabo entula ezikhethekile kakhulu ingqondo izicubu, igazi, futhi blastomeres zygote Mace.

yokukhulisa nucleoli

Isinyathelo zokwenziwa interphase kanye DNA ukufanisana self-kabili kwenzeka okweqa rRNA zofuzo. Njengoba Umsebenzi oyinhloko nucleolus - ukukhiqizwa kwe ribosomes, mayelana nesigameko overexpression ka loci DNA abahlebayo ulwazi mayelana RNA landa kakhulu inani lezi organelles. Nucleoproteins, ayihlobene ne-chromosome ziqale ukusebenza autonomously. Ngenxa yalokho - a nucleoli sebuningini e-nucleus kwakhiwa, distancing uqobo kusukela kuma-chromosome nucleolar. Lesi senzakalo ngokuthi yokukhulisa rRNA zofuzo. Eqhubeka ukufunda umsebenzi we nucleolus kuseli, siphawula ukuthi kunazo asebenzayo we zamagama kwenzeka prophase meiotic ka meiosis, lapho oda oocytes lokuqala ingaqukatha nucleoli angamakhulu amaningana.

Ukubaluleka walesi mkhuba iba sobala uma ucabangela ukuthi kusaqalwa embryogenesis: ichoboza futhi blastulation, udinga omningi ribosomes Kuhlanganisa main izinto zokwakha - amaprotheni. Okhulisa - inqubo lalivamile, kuthatha indawo oogenesis, tilokatane, izilwane eziphila emanzini nasezweni, imvubelo, futhi abanye protists.

Histochemical Ukwakheka organelles

Siyaqhubeka isifundo lamaseli eukaryotic futhi izakhiwo zabo, cabanga nucleolus, isakhiwo kanye nemisebenzi zihlobene kakhulu. Litholakala abaqukethwe ezintathu izinhlobo izakhi:

  1. Nukleonemy (Intshebe kumiswa). Ziyakwazi heterogeneous futhi aqukethe fibrils kanye nezigaxa. Njengengxenye kokubili isitshalo futhi isilwane amaseli, nukleonemy ifomu fibrillar izikhungo. lokuphatselene nesakhiwo nemsebenti we nucleolus Cytochemical kubuye sincike therein khona matrix - inethiwekhi inkomba amaprotheni isakhiwo ephakeme yezinhlayiya.
  2. Vacuoles (avelele).
  3. zithutha luyimbudumbudu (nucleolin).

Ngokombono walaba ukuhlaziywa kwamakhemikhali, organoid wakhiwa cishe ngokuphelele RNA namaprotheni futhi DNA kuphela azungeze yayo, ukwakha isakhiwo annular - chromatin okoloyadryshkovy.

Ngakho sesisungule ukuthi isakhiwo se-nucleolus yakhiwa izinhlangano amahlanu luyimbudumbudu futhi fibrillar izikhungo, chromatin, le reticulum amaprotheni futhi obukhulu fibrillar ingxenye.

izinhlobo nucleoli

isakhiwo kwamakhemikhali lezi organelles incike uhlobo cell lapho zikhona, kanye nezici umzimba wabo. Hlukanisa 5 izinhlobo nucleoli kwesakhiwo eziyisisekelo. Umsuka - reticular, ezivamile futhi esibonakala ngokuqina inala obukhulu Clumps fibrillar impahla kanye nucleoproteins nucleons. Inqubo ubhalwe kabusha ulwazi umhleli nucleolar iyasebenza kakhulu, ngakho izikhungo fibrillar abakalungiselelwa ebonakalayo ngaphansi ngesibonakhulu.

Njengoba Umsebenzi oyinhloko nucleolus kuseli - ukuhlanganiswa kwezici subunits ribosomal, zazo zakha organelles amaprotheni-Kuhlanganisa, uhlobo reticular yenhlangano esivela kokubili nezitshalo nezilwane amaseli. Nucleoli uhlobo annular kwenzeka zezinzwa izicubu amaseli: lymphocyte namaseli endothelial, ogama izakhi zofuzo alotshwa rRNA cishe. nucleoli asalayo atholakala amaseli baphelelwa ikhono umbhalo, isibonelo, normoblasts futhi enterocytes.

uhlobo kuhlukaniswa lamaseli esingokwemvelo baye babhekana ukudakwa carcinogens, imithi elwa namagciwane. Ekugcineni, uhlobo compact nucleolar fibrillar izikhungo elinesimo isethi futhi inombolo encane nucleons.

Nucleolar amaprotheni-matrix

Siyaqhubeka ekutadisheni Sakhiwo sangekhatsi izakhiwo ikhenela bese unquma ukuthi iziphi kukhona nemisebenzi nucleolus kuseli umzimba. Kuyaziwa ukuthi ngu-60% ngo-isisindo dry ewela lokhu amaprotheni organelle ezakha chromatin, izinhlayiya ribosomal, kanye amaprotheni efanele nucleolar. Ake sihlole kubo ngokuningiliziwe. Ingxenye proteids ohilelekile ukucutshungulwa - kumiswa ovuthiwe ribosomal RNA. Lezi zihlanganisa i-RNA polymerase 1 futhi nuclease ukuthi ususe ezintathu ngokweqile nazo zonke molecule rRNA. Amaphrotheni fibrillarin elise obukhulu fibrillar ingxenye, futhi njengengonyama nuclease futhi yenza ukucubungula. Enye amaprotheni - nucleolin. Bekanye fibrillarin kuwukuthi PFC futhi FC nucleoli futhi nucleolar umhleli chromosome prophase ka mitosis.

polypeptide okunjalo njengoba nukleofozin elise zone luyimbudumbudu futhi obukhulu fibrillar ingxenye, khona uhlanganyela kwetinhlavu ribosomal 40 S futhi 60 S subunits.

Lisho ukuthini nucleolus

I zamagama RNA ribosomal - umsebenzi oyinhloko okuyinto ukwenza nucleoli. Ngalesi sikhathi, ngo-ubuso bayo (isb ezikhungweni fibrillar) kwenzeka umbhalo yi polymerase enzayimu i-RNA. Ngalesi umhleli nucleolar kwemiqondo amakhulu ribonucleoprotein zangaphambi ribosomes ngokuthi globules. Nakakhuluma ngalabo kwakhiwa subunits ribosomal ukuthi ngokusebenzisa ikhule ezimbotsheni yenuzi futhi ushiye karyoplasm ngokwabo e le cytoplasm cell. I 40s subunit encane ixhunywe RNA isithunywa, futhi kuphela ngemva kokuba ukuthi enkulu subunit 40s unamathele kubo. Image of a ribosome ovuthiwe okwazi ukusakaza - ukuhlanganiswa kwezici amaprotheni yeselula.

Kulesi sihloko thina isakhiwo nucleolar futhi umsebenzi wahlolwa ngezitshalo nangezilwane amaseli.

Similar articles

 

 

 

 

Trending Now

 

 

 

 

Newest

Copyright © 2018 zu.unansea.com. Theme powered by WordPress.