Umjikelezo wamaseli uyinqubo eyisisekelo ehlanganisa uchungechunge lwezigaba eziphindaphindwa njalo kumaseli ezinto eziphilayo. Lezi zigaba, ezaziwa ngokuthi i-5 Stages Yomjikelezo Weseli, ilawula ngokuqinile ukuphila nokufa kwengqamuzana, ngaleyo ndlela iqinisekise ukukhula, ukuzala kanye nokugcinwa kwayo okufanele. Kulesi sihloko, sizohlola ngasinye salezi zigaba ngokuningiliziwe ngokombono wezobuchwepheshe, sinikeze umbono ongachemile wokuthi le nqubo yeselula eyinkimbinkimbi yenzeke kanjani.
Isingeniso kumjikelezo weseli
El umjikelezo weseli Kuyinqubo eyinkimbinkimbi neqhubekayo evumela amangqamuzana ukuba akhule, azilungise, futhi ahlukane ngendlela elawulwayo. Lo mjikelezo uqukethe izigaba ezihlukene eziphindaphindwayo ngomjikelezo kuwo wonke amaseli omzimba. Ngokuhlukana kwamaseli, amaseli angakwazi ukuphindaphinda futhi akhiqize amaseli amasha ukuze athathe indawo yamaseli awonakele noma agugile.
Izigaba zomjikelezo wamaseli zihlukaniswe izigaba ezimbili eziyinhloko: isigaba se-interphase kanye nesigaba sokuhlukaniswa kwamaseli. Ngesikhathi se-interphase, iseli liyakhula futhi lilungiselele ukuhlukaniswa ngama-subphase ahlukene, njengesigaba se-G1, isigaba se-S, nesigaba se-G2. Esigabeni sokuhlukaniswa kwamaseli, iseli lihlukana libe amaseli amantombazane amabili ngokusebenzisa i-mitosis noma i-meiosis, kuye ngohlobo lweseli.
Phakathi nesigaba se-G1 se-interphase, iseli likhula ngokuphawulekayo futhi liqongelela izinto ezidingekayo zokuhlukaniswa kwamaseli. Esigabeni sika-S, ingqamuzana liphinda i-DNA yalo, liqinisekise ukuthi ingqamuzana ngalinye lendodakazi lithola ikhophi eliphelele lezakhi zofuzo. Ekugcineni, esigabeni se-G2, iseli lilungiselela ukwehlukana ngokuqeda amalungiselelo okugcina. Lesi sigaba sihlanganisa nokuhlola nokulungisa amaphutha okungenzeka ku-DNA ngaphambi kokuhlukaniswa kwamaseli.
Ngokufigqiwe, umjikelezo weseli Kuyinqubo ebalulekile yokuphila kwamangqamuzana. Ngalo mjikelezo, amaseli angakhula, aziphindaphinde, futhi azilungise ngokuphumelelayo. Ukuqonda izigaba ezihlukene zomjikelezo wamaseli kubalulekile ukuze kufundwe izinqubo ezihlukahlukene zebhayoloji, njengokuthuthukiswa kombungu, ukuvuselelwa kwezicubu nokuvimbela umdlavuza.
Izigaba zomjikelezo weseli ngokuningiliziwe
Umjikelezo wamaseli uyinqubo eyinkimbinkimbi ehlukaniswa izigaba ezihlukene, ngasinye sinomsebenzi waso othize. Kulesi sigaba, sizohlola ngokuningiliziwe izigaba ezahlukene ingqamuzana elidlula kuzo phakathi nomjikelezo wempilo yayo.
1. Isigaba se-G1 (Igebe 1): Phakathi nalesi sigaba, iseli lilungiselela ukuphindaphinda kwe-DNA. Kulesi sigaba, ukukhula nokwanda kosayizi wamaseli kwenzeka, kanye nokuhlanganiswa kwamaprotheni ne-RNA. Kuyisigaba esibalulekile, njengoba izimo zamaselula zihlolwa ngaphambi kokudlulela esinyathelweni esilandelayo. Uma umonakalo we-DNA utholwa, iseli lingamisa umjikelezo futhi lingene esimweni sokuphumula esaziwa ngokuthi isigaba se-G0.
2. S Isigaba (Ukwenziwa): Kulesi sigaba, ukuhlanganiswa kwe-DNA kwenziwa ngokuphindwaphindwa ncamashi kwe-molecule yokuqala. I-DNA iphindaphinda i-semiconservative, okungukuthi, umucu wokuqala ngamunye usebenza njengesifanekiso sokwakheka kwentambo entsha ehambisanayo. Le nqubo Kubalulekile ukuqinisekisa ukuthi ingqamuzana ngayinye yendodakazi entsha ithola ikhophi ephelele nenembile yezakhi zofuzo.
3. Isigaba se-G2 (Igebe 2): Phakathi nalesi sigaba, iseli lilungiselela ukuhlukaniswa kwamaseli. Umjikelezo omusha weprotheyini kanye nokuhlanganiswa kwe-RNA kwenzeka, futhi i-DNA eyimpinda iqinisekiswa ukuthi ayinawo amaphutha noma umonakalo Ukwengeza, ukuhlolwa kwezimo zamaselula kuyenziwa ukuze kuqinisekiswe ukuthi wonke amaprotheni nezinto ezidingekayo zikhona ngaphambi ukuqhubekela phambili kuqhubekela phambili. isigaba esilandelayo: ukuhlukaniswa kwamaseli noma isigaba se-M.
I-Interphase: Ukulungiselela ukuhlukaniswa kwamaseli
I-Interphase yisigaba esibalulekile emjikelezweni weseli lapho iseli lilungiselela ukuhlukana phakathi nalesi sikhathi, iseli libhekana nezinqubo ezihlukahlukene eziqinisekisa ukuphindwaphindwa okufanele kwezakhi zofuzo kanye nokusatshalaliswa okufanele kwamaselula. I-interface ingahlukaniswa izigaba ezintathu ezihlukene: isigaba se-G1, isigaba sika-S kanye nesigaba se-G2. Lezi zigaba zidlala indima ebalulekile ekukhuleni okufanele nasekusebenzeni kweseli.
Esigabeni se-G1, ingqamuzana lisesimeni sokukhula kanye nomsebenzi oshubile we-metabolic. Ngalesi sikhathi, iseli lihlanganisa amaprotheni futhi liqongelela amandla enqubweni ezayo yokuhlukanisa Ngaphezu kwalokho, kulesi sigaba ubuqotho be-DNA buqinisekisiwe futhi ukulungiswa kuyenziwa uma kwenzeka umonakalo. Uma iseli lihlangabezana nazo zonke izidingo, lizodlulela esigabeni sika-S.
Isigaba S, esaziwa ngokuthi yi-DNA synthesis phase, sibalulekile ekukhiqizeni amaseli. Phakathi nalesi sigaba, i-DNA etholakala kuyi-nucleus yengqamuzana iphindeke kabili ngokuphelele. Le nqubo yenziwa ngokunemba nangokwethembeka, njengoba noma iliphi iphutha lingase libangele ukuguqulwa kofuzo. Uma i-DNA isiphindaphindwe, iseli liqhubekela esigabeni se-G2, lapho amalungiselelo okuhlukaniswa kwamaseli eqhubeka khona. Kafushane, i-interphase iqinisekisa ukuthi iseli selilungile futhi lisesimweni esifanele ngaphambi kokuqala ukuhlukana kwamaseli, ngaleyo ndlela iqinisekise ifa elilungile kanye nokusebenza kwamaseli endodakazi.
Isigaba M: I-Mitosis nezigaba zayo ezibalulekile
Isigaba esingu-M siyinqubo ebalulekile ekuhlukaniseni amaseli enesibopho sokuphindaphinda nokusabalaliswa kwezinto zofuzo. Kuhlanganisa izigaba eziyinhloko ezihlukene eziqinisekisa ukuhlukaniswa okufanele kwama-chromosome kanye nokwakheka kwamangqamuzana amantombazane amabili afana neseli likamama.
Ngaphakathi kwesigaba esingu-M, izigaba ezibalulekile ze-mitosis zifaka:
- I-Prophase: Lesi sigaba sibonakala ngokufiphala kwama-chromosome kanye nokuba buthakathaka kwemvilophu yenuzi. Ngaphezu kwalokho, ama-centrioles ahlukana futhi athuthele kumapali aphambene seseli.
- I-Metaphase: phakathi nalesi sigaba, ama-chromosome aqondana endizeni ye-equatorial yeseli, enze ipuleti le-metaphase. Ama-Mitotic spindle microtubules axhumeka ku-centromeres ye-chromosome ngayinye, awalungisela ukuhlukana kwawo okulandelayo.
- I-Anaphase: Kulesi sigaba, ama-centromere ahlukana, okuvumela ama-chromosome angudade ukuthi athuthele ezigxotsheni eziphambene zeseli. Ukudonsa kwama-microtubules we-mitotic spindle kuqinisekisa ukuhlukaniswa okulungile kwama-chromosome.
Isigaba esingu-M sifinyelela umvuthwandaba nge-telophase, lapho ama-chromosome afinyelela khona izigxobo eziphambene zeseli futhi imvilophu yenuzi entsha iqala ukwakheka eduze kwesethi ngayinye ye-chromosome. Ekugcineni, i-cytokinesis ihlukanisa i-cytoplasm, okuholela ekwakhekeni kwamangqamuzana endodakazi aphelele amabili afana ngofuzo nengqamuzana likamama.
I-Cytokinesis: Ukuhlukaniswa kwe-cytoplasm
I-Cytokinesis inqubo lapho i-cytoplasm yeseli ihlukana khona ngemva kokuhlukana kwama-chromosome ngesikhathi se-mitosis. Kuyisigaba esiyisisekelo sokuhlukaniswa kwamaseli esiqinisekisa ukwakheka kwamangqamuzana amantombazane amabili afana ngokofuzo. Ngesikhathi se-cytokinesis, kwakhiwa izakhiwo ezikhethekile ezisiza ekuhlukaniseni okuqondile kwe-cytoplasm.
Esinye sezakhi ezibalulekile ezihilelekile ku-cytokinesis iyindandatho yenkontileka, eyakhiwe amaprotheni okuthiwa i-actin ne-myosin. Le ndandatho "yakha" eduze kwenkabazwe yeseli futhi inkontileka ukuze inciphise iseli futhi ekugcineni ihlukanise kabili. Ukwakheka nokufinyela kweringi yenkontileka kulawulwa uchungechunge lwezimpawu zamangqamuzana eziqinisekisa ukuhlukana kwamaseli okunembayo nokulawulwayo ngokwesikhathi nendawo.
Ngaphezu kwendandatho yenkontileka, kunezinye izindlela ezengeziwe ezifaka isandla ku-cytokinesis ezinhlotsheni ezahlukene zamaseli nezinto eziphilayo. Ngokwesibonelo, kwamanye amangqamuzana ezitshalo, i-cell plate yakheka enkabazwe bese iba i-cell plate entsha. udonga lweseli okuhlukanisa amaseli amantombazane amabili. Ngakolunye uhlangothi, emangqamuzaneni ezilwane, ama-vesicle olwelwesi olubizwa ngokuthi ama-cytokinesis vesicle akheka futhi ahlangane enkabazwe yengqamuzana akhe ulwelwesi lwamangqamuzana amantombazane amabili.
Ukubaluleka kokulawulwa komjikelezo weseli
Umjikelezo umakhalekhukhwini kuyinqubo kubalulekile ekunakekeleni nasekuphileni kwezinto eziphilayo, njengoba kuvumela ukuzala nokukhula kwamangqamuzana. Ukulawulwa komjikelezo wamaseli kubaluleke kakhulu, njengoba kuqinisekisa ukuthi isigaba ngasinye senziwa ngendlela enembile nedidiyelwe. Ngaphandle kwalo mthethonqubo, kungenzeka amaphutha angaba nemiphumela emibi kakhulu, njengokwakheka kwezimila noma ukukhubazeka kofuzo.
Ukulawulwa komjikelezo weseli kwenziwa ngesenzo samaprotheni nama-molecule ahlukene asebenza njengamaswishi nezinzwa zokulawula ukuqhubeka komjikelezo. Lezi zindlela zokulawula ziqinisekisa ukuthi amangqamuzana ahlukana ngendlela efanele, i-DNA iphindaphindwa ngokwethembeka, futhi ibhalansi igcinwa phakathi kwezigaba zokukhula nokuhlukana kwamangqamuzana. Ukuntuleka kokulawulwa komjikelezo wamaseli kungaholela ezifweni ezinjengomdlavuza.
Ilele ekhonweni layo lokuvimbela nokulungisa amaphutha ofuzo. Phakathi nomjikelezo wamaseli, amaseli aba nethuba lokulungisa noma yikuphi ukonakala ku-DNA ngaphambi kokuqhubeka nokuhlukana. Ukulawulwa okufanele komjikelezo weseli uqinisekisa ukuthi amaseli awonakele alungiswa kahle noma, uma lokhu kungenzeki, akhishwe emzimbeni. Ngaphezu kwalokho, ukulawula umjikelezo weseli kuphinde kuvimbele ukuhlukana kwamaseli ngokweqile, okungaholela ezinkingeni zempilo ezifana nokukhula kwezicubu okungavamile noma izimila.
Ukungalingani emjikelezweni wamaseli kanye nomthelela wawo ezifweni
Ukungalingani emjikelezweni weseli sekuphenduke "isihloko esibaluleke kakhulu" ekutadisheni izifo zabantu. Lokhu kungalingani ekulawuleni umjikelezo weseli kungaba nomthelela obalulekile ekuthuthukisweni nasekuqhubekeleni phambili kwezifo ezihlukahlukene, kusukela kumdlavuza kuya ezifweni ze-neurodeergenerative.
Okunye kokungalingani okuyinhloko emjikelezweni weseli Kuwukuvela koguquko ezakhini zofuzo ezinomthwalo wemfanelo wokulawula inqubo yokuhlukaniswa kwamaseli. Lezi zinguquko zingenzeka ngokuzenzakalelayo noma zenziwe izinto zangaphandle njengemisebe noma amakhemikhali athile. Lapho ukuguqulwa kwezakhi zofuzo kwenzeka kulezi zakhi zofuzo, ingqamuzana lingalahlekelwa amandla ayo okulawula kahle umjikelezo wengqamuzana layo, okungaholela ekwandeni kwamangqamuzana okungalawuleki nokuthuthukiswa kwezimila.
Okunye ukungalingani okubalulekile kumjikelezo weseli ukuguqulwa kwezindlela zokulungisa i-DNA. Lapho i-DNA yonakalisiwe, amaseli avula izindlela zokulungisa ukuze alungise lezi zinto ezingavamile. Kodwa-ke, kwezinye izimo, lezi zindlela zingase zibe sengozini, okuholela ekuqongeleleni komonakalo we-DNA. Lokhu kunqwabelana kokulimala kofuzo kungabangela ukwehluleka kumjikelezo weseli futhi kukhuthaze ukuthuthukiswa kwezifo zofuzo ezizuzwe njengefa noma ezitholiwe.
Izincomo zokuqonda kangcono izigaba zomjikelezo weseli
Kwisayensi yebhayoloji yamaseli, ukuqonda izigaba zomjikelezo weseli kubaluleke kakhulu ukuze uqonde izinqubo ezibalulekile ezenzeka kumaseli.
1. Ikhuthaza ukufunda okubonakalayo: Umjikelezo wamaseli uyinqubo eyinkimbinkimbi ehlanganisa izigaba ezihlukahlukene, njenge-interphase, mitosis kanye ne-cytokinesis. Ukuze uhlanganise kangcono lezi zigaba, kuyatuseka ukusebenzisa imidwebo, ukugqwayiza namamodeli anezinhlangothi ezintathu. Lezi zinsiza ezibukwayo zizokusiza ukuthi ubone ngeso lengqondo ngokucacile nangokunembile izehlakalo ezehlukene ezenzeka phakathi nesigaba ngasinye.
2. Sungula ukuxhumana phakathi kwezigaba: Ukuze uqonde ngokugcwele umjikelezo weseli, kubalulekile ukuqonda ukuthi izigaba ezahlukene zixhunywe kanjani komunye nomunye. Isibonelo, i-interphase isikhathi somsebenzi omkhulu wamaselula, lapho ukuphindwaphindwa kwe-DNA kwenzeka, kuyilapho i-mitosis iyisigaba sokuhlukaniswa kwamaseli ngokwawo. Ukusungula lokhu kuxhumana kuzokuvumela ukuthi ujabulele ukulandelana okunengqondo nenjongo yesigaba ngasinye.
3. Zibuyekeze ngocwaningo lwesayensi: Ukuqonda izigaba zomjikelezo weseli kuyisihloko esishintsha njalo. Imininingwane emisha kanye nezindlela ezihambisana nesigaba ngasinye kutholakala njalo. Ngakho-ke, kuyalulekwa ukuthi uhlale unolwazi lwakamuva ngokuthuthuka kwesayensi futhi ufunde izindatshana zesayensi ezisesikhathini samanje. Ukuqaphela ucwaningo lwakamuva kuzokusiza uqonde kangcono ubunkimbinkimbi bezigaba zomjikelezo wamaseli kanye nemithelela enawo empilweni nasekuthuthukisweni kwezinto eziphilayo.
Imibuzo Nezimpendulo
Umbuzo: Yiziphi izigaba zomjikelezo weseli?
A: Izigaba zomjikelezo wamaseli ziwuchungechunge lwezigaba amaseli adlula kuzo emjikelezweni wawo wempilo. Lezi zigaba zihlanganisa i-interphase kanye ne-mitosis.
Q: Yiziphi izigaba ze-interface?
A: I-interface inezigaba ezintathu: isigaba se-G1, isigaba sika-S, kanye nesigaba se-G2.
Q: Kwenzekani phakathi nesigaba se-G1 se-interphase?
A: Phakathi nesigaba se-G1, iseli liyakhula futhi lilungiselele ukuphindaphinda i-DNA yalo.
Q: Kwenzekani ngesikhathi S isigaba sesixhumi esibonakalayo?
IMP: Phakathi nesigaba sika-S, ingqamuzana lihlanganisa ikhophi enembile ye-DNA yalo, liphindaphinde izinto zalo zofuzo.
Q: Yini eyenzekayo phakathi nesigaba G2 sesixhumi esibonakalayo?
A: Phakathi nesigaba se-G2, iseli liyaqhubeka nokukhula futhi lilungiselela ukuhlukaniswa kweseli.
Umbuzo: Yiziphi izigaba ze-mitosis?
A: I-Mitosis inezigaba ezine: i-prophase, i-metaphase, i-anaphase ne-telophase.
Q: Kwenzekani ngesikhathi se-prophase?
A: Ngesikhathi se-prophase, ama-chromosome ayajiya futhi i-mitotic spindle iqala ukwakheka.
Q: Kwenzekani phakathi ne-metaphase?
IMP: Phakathi ne-metaphase, ama-chromosome aqondana endizeni ye-equatorial yeseli.
Q: Kwenzekani ngesikhathi se-anaphase?
A: Ngesikhathi se-anaphase, ama-chromatids angudade ayahlukana futhi athuthele ezigxotsheni eziphambene zeseli.
Q: Kwenzekani ngesikhathi se-telophase?
A: Phakathi ne-telophase, ama-chromosome afinyelela ezigxotsheni eziphambene zeseli futhi ahlehle, enze ama-nuclei amabili ahlukene.
Q: Kwenzekani ngemva mitosis?
A: Ngemva kwe-mitosis, iseli liyahlukana nge-cytokinesis, lihlukanise libe amaseli amadodakazi amabili afana ngokofuzo.
Umbuzo: Kungani izigaba zomjikelezo weseli zibalulekile?
A: Izigaba ze cell umjikelezo kukhona kubalulekile ngoba avumela ukukhula nokukhiqizwa kabusha kwamaseli ngendlela ehlelekile nelawulwayo. Lezi zigaba ziqinisekisa ukuphindwaphindwa okulungile kwe-DNA kanye nokusatshalaliswa ngokulinganayo kwama-chromosome kumaseli endodakazi.
Ukuqaphelwa Kokugcina
Kafushane, umjikelezo weseli uqukethe izigaba ezinhlanu ezichazwe ngokucacile eziqinisekisa ukuphindaphinda okulungile nokuhlukaniswa kweseli. Lezi zigaba, okuyilezi: G1, S, G2, mitosis kanye ne-cytokinesis, zisebenza ndawonye ukuze kugcinwe i-homeostasis nokugcina ubuqotho bofuzo ezintweni eziphilayo. Ngokulawulwa okunembile kwezinqubo zokulawula nokubamba iqhaza okusebenzayo kwamaprotheni nama-enzyme ahlukene, umjikelezo weseli wenziwa ngendlela ephumelelayo nedidiyelwe.
Kubalulekile ukugqamisa ukuthi noma yikuphi ukuguqulwa kule nqubo elawulwa kakhulu kungaba nemiphumela ebalulekile empilweni nasekuthuthukisweni kwezinto eziphilayo Ngakho-ke, ukuqonda izigaba zomjikelezo wamaseli kubalulekile ocwaningweni nasekwelapheni kwezifo ezihambisana nokuhlukaniswa kwamaseli okungalawuleki. njengomdlavuza.
Ngenxa yentuthuko yesayensi nezobuchwepheshe, kube nokwenzeka ukuthola ulwazi oluthe xaxa mayelana nezisekelo zamangqamuzana ezisekela umjikelezo wamangqamuzana kanye namasu okwelapha angamelana nokungasebenzi kahle okungenzeka. Nokho, kusekuningi okumele kutholwe futhi sikuqonde mayelana nale nqubo eyisisekelo yokuphila.
Sengiphetha, izigaba ezinhlanu zomjikelezo weseli zihlinzeka ngohlaka oluhlelekile lokuphindaphinda kweseli nokuhlukaniswa. Ukuqonda kwayo okunembe nokuningiliziwe kusivumela ukuthi singagcini nje ukwazisa inkimbinkimbi nokunemba kwezwe lamaselula, kodwa futhi kusinikeza ithuba lokuthuthukisa ucwaningo nemithi yokwelapha ethuthukisa izinga lethu lokuphila nokuphila kahle.
Ngingu-Sebastián Vidal, unjiniyela wekhompyutha ozifelayo ngobuchwepheshe kanye ne-DIY. Ngaphezu kwalokho, ngingumdali we tecnobits.com, lapho ngabelana khona ngezifundo zokwenza ubuchwepheshe bufinyeleleke kakhudlwana futhi buqonde wonke umuntu.