Timphawu tesakhiwo zenuzi. Ukwakheka nemisebenzi kuyi-nucleus yengqamuzana

iseli nucleus - organelle ngendlela ebaluleke kakhulu, endaweni wesitoreji nokukhiqizwa ukwaziswa kwezakhi zofuzo. Lesi sakhiwo ulwelwesi, okuyinto oluthatha 10-40% sezitokisi, ogama imisebenzi abaluleke kakhulu ngenxa yokuphila eukaryotes. Nokho, ngisho ngaphandle kobukhona ukwaziswa kwezakhi zofuzo-Kernel ukuqaliswa kungenzeka. Isibonelo salokhu inqubo yikhono ukuphila amaseli virus. Noma kunjalo, izici isakhi nucleus futhi injongo yawo ibaluleke kakhulu a amaningi.

Indawo nucleus esitokisini oyiyo

I-nucleus itholakala ekujuleni cytoplasm futhi ukuthintana ngqo okwe bushelelezi reticulum endoplasmic. Lizungezwe ulwelwesi ezimbili, ahlukaniswe ngesikhala perinuclear. Ngaphakathi matrix ikhenela likhona, ethile chromatin futhi nucleoli.

Ezinye amangqamuzana omuntu ovuthiwe akudingeki nuclei, nabanye usebenze abacindezelwe kakhulu imisebenzi yayo. Ngokuvamile, isakhiwo nucleus (Scheme) umelwe ngalo ingaphakathi zenuzi iphahlwe karyotheca kusukela anama chromatin futhi nucleoli, ilungiswe matrix zenuzi nucleoplasm.

isakhiwo karyotheca

Ukuze kube lula amaseli core, lona wamuva kumele lithathwe ngokuthi Bubbles, kuvinjelwe amagobolondo kusukela nezinye Bubbles. Core - kungcono ibhodlela Imininingwane zofuzo ukushuba cell. Kusukela cytoplasm yalobo kwakuvikela bilayer lipid ulwelwesi. Core igobolondo isakhiwo esifana ulwelwesi yeselula. Eqinisweni, bayehluka kuphela igama kanye nenombolo ye izingqimba. Ngaphandle kwakho konke lokhu, bona Bayefana lokuphatselene nesakhiwo nemsebenti.

Ukwakheka karyotheca (ulwelwesi senuzi) ezimbili ungqimba: yakhiwa izingqimba ezimbili lipid. Bilipidny karyotheca olwelwesini ngqo oxhumana emangelengele endoplasmic reticulum amaseli. karyotheca Yangaphakathi - ne okuqukethwe core. Phakathi kariomembranoy yangaphandle futhi kwangaphakathi isikhala perinuclear ukhona. Ngokusobala, kwamiswa ngenxa imihlola electrostatic - umuzwa wokwenyanya osongoza glycerol izinsalela.

Umsebenzi we ulwelwesi yenuzi ukudala isithiyo mechanical phakathi nucleus futhi cytoplasm. Umnyombo kwangaphakathi indawo ulwelwesi nenkanuko edlulele-matrix yenuzi - chain amaprotheni molecule isekele lesi sakhiwo ngakuthathu. Ulwelwesi ezimbili yenuzi babe ikhule ezimbotsheni ekhethekile: ngabo kuya ribosomes ku cytoplasm isithunywa amahlamvu RNA. Ngesikhathi ukujiya core kakhulu nucleoli eziningana futhi chromatin.

Isakhiwo sangaphakathi nucleoplasm

Timphawu tesakhiwo zenuzi asivumela ukuba ukuqhathanise iseli. Ngaphakathi kuyi-nucleus ukhona endaweni ekhethekile (nucleoplasm) oluthunyelwe sol-gel, isixazululo amaprotheni colloidal. Ngaphakathi kuwo kukhona nucleoskeleton (-matrix), emelelwa amaprotheni fibrillar. Umehluko main siqukethe kuphela ukuthi amaprotheni esidi abakhona ikakhulu kuyi-nucleus. Ngokusobala, endaweni enjalo ukuphendula kudingeka alondoloze izakhiwo amakhemikhali acid nucleic futhi ukusabela kwamakhemikhali.

endosome

Isakhiwo kuyi-nucleus yengqamuzana akukwazi ukuqedelwa ngaphandle nucleoli. Im iyona Helical RNA ribosomal, esemgwaqweni esigabeni yokuvuthwa. Kamuva, kusukela kuye uthole ribosome - i organelle ezidingekile amaprotheni zamagama. isakhiwo I nucleolus isehlane has izingxenye ezimbili: fibrillar futhi globular. Ziyahlukahluka kuye kuphela electron microscopy, futhi akudingeki ulwelwesi yabo.

ingxenye Fibrillar itholakala maphakathi nucleolus. Limelela uhlobo ribosomal RNA Strand okuzokwenziwa kuqoqwa subunit ribosomal. Uma sicabangela umongo (lokuphatselene nesakhiwo nemsebenti), kusobala ukuthi uzobe kwakhiwa enye ingxenye luyimbudumbudu kamuva. Lawa efanayo ukukhula ribosomal subunit, okuyizinto ezigabeni kamuva sokuthuthuka. Kulezi ribosomes akhiwa ngokushesha. Basuke asuswe nucleoplasm ngokusebenzisa yenuzi ikhule ezimbotsheni karyotheca futhi iwele ulwelwesi of anolaka reticulum endoplasmic.

Chromatin futhi Ngokuvamile ama-chromosome

Sakhiwo umsebenzi nucleus amaseli organically ukuxhunywa:-ke likhona kuphela lezo zakhiwo ezidingekayo ukuze isitoreji nokukhiqizwa ukwaziswa kwezakhi zofuzo. Futhi kukhona karioskelet (-matrix core) ogama umsebenzi silondoloze organelles ukuma. Nokho, ingxenye ebaluleke kakhulu chromatin-nucleus. Lokhu-chromosome, edlala indima ikhadi izinkomba bezinhlanga ezahlukene lokhu ngezakhi ezingamaqoqo.

Chromatin kuyinto amaprotheni eziyinkimbinkimbi esakhiwa isakhiwo quaternary we polypeptide kuhambisane a nucleic acid (RNA noma i-DNA). I plasmids chromatin amagciwane futhi samanje. Cishe ingxenye yesine ka inani isisindo up chromatin histones - amaprotheni obhekene "emaphaketheni" ulwazi zofuzo. Lesi sici izifundo biochemistry eziphilayo. Isakhiwo eziyinkimbinkimbi core yingenxa khona chromatin futhi icubungula kushintshanisa spiralization futhi uncoiling.

Ukuba khona histone kwenza kube nokwenzeka ukuba uphenduke futhi umphelelisi umucu DNA endaweni encane - ku kuyi-nucleus yengqamuzana. Lokhu kwenzeka ngale ndlela: histones ukwakha nucleosomes, okuyizinto izinhlangano ezifana ubuhlalu. H2B, H3, H4 futhi H2A - lawa main histone amaprotheni. Nucleosome ezakhiwe emaphahla lamane ngayinye histones ethulwa. H1 Ngakho histone kuyinto linker: exhunywe DNA endaweni ukungena e ku nucleosome. emaphaketheni DNA kuwumphumela "emazombezombe" komugqa-molecule 8 isakhiwo histone amaprotheni.

Isakhiwo nucleus, ogama sikimu eboniswe ngenhla kusikisela solenoidpodobnoy isakhiwo DNA ifakwe ku histones. I ukushuba we nhlanganisela imayelana 30 NM. Isakhiwo kungenzeka wafingqa futhi eminye ukuba luthathe isikhala esincane wadalula umonakalo mechanical nakanjani ezenzeka phakathi iseli ukuphila.

I kukhishwa nezingxenyana ezithile chromatin

Isakhiwo, isakhiwo kanye umsebenzi kuyi-nucleus yengqamuzana fixated ngalolo ukwesekwa izinqubo ashukumisayo Helix futhi uncoiling ka chromatin. Ngoba kukhona amafraktjhini ezimbili eziyinhloko zalo malini Helical (heterochromatin) kanye malospiralizovannaya (euchromatin). Bahlukene kokubili ikhipha futhi okusebenza. Ngo-DNA heterochromatin is kahle bavikelekile yimuphi umthelela futhi ayikwazi ukuthi ibe amagama. Euchromatin ekuvikeleni ababuthaka, kodwa izakhi zofuzo kungenziwa kabili ngoba amaprotheni zamagama. Ngokuvamile sites heterochromatin futhi euchromatin kuthiwa alternated lonke ubude yonke we-chromosome.

chromosome

I kuyi-nucleus yengqamuzana, isakhiwo kanye nemisebenzi echazwe kule ncwadi yakhiwa chromosome. Lena chromatin eziyinkimbinkimbi futhi ezinabantu phama ukuthi kuyabonakala ngaphansi microscopy ukukhanya. Nokho, lokhu kungenzeka kuphela uma slide isendaweni iseli isinyathelo mitotic noma division meiotic. Omunye izigaba kuyinto Helix ka chromatin ukwakha chromosome. Ukwakheka kwazo ngokwama-silula: chromosome has a telomere nezingalo ezimbili. Ngamunye amaningi elilodwa zinhlobo isakhiwo efanayo nucleus. Ithebula-chromosomes naye efanayo.

Ukuqaliswa imisebenzi ebalulekile

Izici eziyinhloko umnyombo isakhiwo elihlobene ne ukuqaliswa abanye imisebenzi kanye nesidingo ukuyilawula. I-nucleus uba onalo ukwaziswa kwezakhi zofuzo, okungukuthi uhlobo lwefayela eziqoshiwe zonke ukulandelana acid acid amaprotheni ukuthi kwemiqondo kuseli. Kusho sokwenza umsebenzi, iseli kumelwe synthesize isakhiwo amaprotheni ufakwe ku isakhi sofuzo.

Umnyombo "uyayiqonda" lokho amaprotheni ethile kwemiqondo ngesikhathi esifanele, kukhona uhlelo wangaphandle (ulwelwesi) kanye ama-receptor yangaphakathi. Ulwazi kubo ihlinzekwa umnyombo esebenzisa omoya yamangqamuzana ezinto eziphilayo. Ngokuvamile lokhu kwenziwa ngokusebenzisa indlela adenylate cyclase. Njengoba amaseli bavezwa hormone (epinephrine, norepinephrine), kanti ezinye zezidakamizwa isakhiwo hydrophilic.

A yesibili nokwaziswa transmission indlela ingaphakathi. He is eziyizici molecule lipophilic - corticosteroids. Le into bilipidnuyu lingena ulwelwesi cell futhi siqondiswe nucleus, lapho baxhumana yokwamukela yayo. Ngenxa ukusebenza kwawo eziyinkimbinkimbi yokwamukela esisogwini ulwelwesi cell (adenylate cyclase indlela) noma karyotheca, ukuphendula iqala ukusebenza isakhi esithile. It replicates, isithunywa RNA yakhiwa ngesisekelo yalo. Kamuva, ngokuvumelana yakamuva kwemiqondo amaprotheni isakhiwo eyenza umsebenzi.

Umnyombo eziphilayo ezinamangqamuzana amaningi

Ngo ezinamangqamuzana amaningi umzimba ethile core isakhiwo ziyefana ku owumphumela. Nakuba zikhona izici ezithile umehluko wemisindo nemiqondo yamagama. Okokuqala, ezinamangqamuzana amaningi kusho ukuthi umsebenzi wayo okhethekile siqu (noma ngaphezulu) kuzobekwa obala eziningi amaseli. Lokhu kusho ukuthi abanye izakhi zofuzo kukhona despiralizovany unomphela, kuyilapho abanye esimweni sokungasebenzi.

Ngokwesibonelo, amangqamuzana kwezicubu adipose amaprotheni zamagama ngizoya ngasebenzi, ngakho-ke iningi chromatin spiralized. Futhi amaseli, isibonelo, exocrine amaprotheni pancreatic izinqubo biosynthetic uqhubeke njalo. Ngenxa chromatin yabo despiralizovan. Kulezi zindawo, izakhi zofuzo kuthiwa ziphindaphindwe kaningi. Kulesi sici kubalulekile ukhiye: isethi chromosome yazo zonke emangqamuzaneni omzimba uyefana. Kuphela ngenxa kwamangqamuzana nemisebenzi izicubu ezinye zazo emsebenzini, nezinye dispiralized abanye kakhulu.

amaseli Nuclear-mahhala umzimba

Kukhona cell, izici isakhi ikhenela ayikwazi kubhekwe ngoba ziwumphumela ukuphila kwabo noma zivimbele umsebenzi walo, noma ngokuphelele ayibulale. Isibonelo elula - amangqamuzana abomvu egazi. Lokhu egazi, ingxenye eyinhloko kusukela lapho abakhona kuphela kusaqalwa yentuthuko, lapho kuhlelwe umqondo-hemoglobin. Uma ubukhulu bayo kumanele ukudluliswa oksijini, nucleus esuswa amaseli, ukuze kube lula zokuhamba yayo kungaphazamisi umoya-mpilo.

Injalo jikelele erythrocyte isikhwama cytoplasmic egcwele elithwala umoya-mpilo. Sakhiwo efanayo futhi isici amaseli fat. Ukwakheka adipocyte iseli nucleus lula kakhulu, it incipha futhi ukuqhela ukuze ulwelwesi, namaprotheni zamagama izinqubo kukhona Ubuningi bamahora engasenamahloni. La mangqamuzana nazo okusikhumbuza "izikhwama" bagcwala amafutha, nakuba Yiqiniso, ukusabela okuhlukahlukene kwamakhemikhali zithé kunangendlela amangqamuzana abomvu egazi. Ama-platelet I futhi awanayo i-nucleus, kepha kumele kungathathwa njengesigwebo amaseli agcwele. Lokhu cell izingcezwana ezidingekayo ukuze kuqalise ukusebenza inqubo hemostasis.