Selo adzizungulira, chitetezo chokwanira, selo envelopu

Kukhalako kwa nthawi foni kuchokera tsiku la mapangidwe ake ndi kugawa mayi selo magawano yake kapena imfa amatchedwa akuti "selo mkombero". Mu nthawi zosiyanasiyana osiyana khungu. Mwachitsanzo, woyambira ndi hematopoietic maselo za m'mimba ang'ono ndi khungu amatha kulowa mkombero selo iliyonse maola 12-16, iwo mwamsanga zikupitiriza mu zamoyo wamkulu. Short m'zinthu moyo maselo otsiriza mphindi 30, kudzachitika pamene kuphwanya mofulumira mazira achule, echinoderms ndi nyama zina. A ambiri mitundu chikhalidwe selo zinthu komanso selo mkombero ali aafupi nthawi ya mphindi 20. Pa mlingo chakhala chikugwiritsidwa ntchito mwakhama kugawa nthawi maselo nthawi pakati mitoses ndi maola 10 kuti 24.

Mbali ndi nthawi ya mkombero selo. Cell mkombero wa nyama ndi zomera imakhala nthawi ziwiri: interphase (nthawi ya mapuloteni kaphatikizidwe ndi DNA) ndi mitosis (cell magawano mkombero). Interphase zikuphatikizapo nthawi zingapo:

1. G1-gawo - nyengo ya kukula, imene kaphatikizidwe mapulotini, RNA ndi m'nyanjazi zina selo.

2. S-gawo - mu imeneyi izi zimachitika kaphatikizidwe interphase wocheperapo kwa DNA a mtima selo, ndi anawaonjezera kuwirikiza kawiri wa organelles okhudza maselo ambiri (centrioles);

3. G2-gawo - nthawi imene pali pokonzekera mitosis.

Maselo kuti salinso kugawanitsa, G1-gawo mwina kwina, mu nthawi iyi, iwo ali gawo mpumulo (G0).

The ndondomeko ya kugawikana selo (mitosis) lili ndi mbali ziwiri:

1. Kudulidwa kwa phata selo - mitosis.

2. Chigawo cha cytoplasm selo - cytokinesis.

Lamulo la ntchito foni. Kusintha nthawi selo mkombero kumachitika pamene zimavuta mapuloteni - cyclins ndi cyclin amadalira kinases. Maselo G0 gawo angathe kulowa kuzungulira mchikakamizo cha zinthu zosiyanasiyana kukula. Epidermal, ndi zinthu kupatsidwa zinthu za m'mwazi-linachokera ndi mitsempha kukula chinthu, ali zimachitika nthawi zonse ndi maselo lotengeka dongosolo okhudza maselo ambiri kusonyeza kuti kumabweretsa galamafoniyo mapulotini mbewu. Pa kinases Zingakhalenso umagwira ntchito mwa mogwirizana ndi cyclins yeniyeni, zili zomwe zikusintha mu kuzungulira.

Kusokonezeka kwa lamulo yachibadwa ya kayendedwe ka maselo zikubweretsa mapangidwe zotupa olimba. Mapangidwe zotupa zilonda za p53 mapuloteni ali ndi udindo: Zimathandiza mapuloteni kaphatikizidwe p21, womwe kumabwezera mmbuyo ndi CDK cyclin zovuta, kumene kumakhala kumabweretsa selo mkombero kumangidwa mu G1 ndi gawo G2. Selo ndi DNA zowonongeka salowa S. Pa gawo cha masinthidwe kutsogolera imfa kapena zosinthidwa za jini mapuloteni p53 zimachokeradi ndi selo mkombero anatseka misewu kulowa mitosis, tingadzifunse maselo owukira, ena amene aphedwa, ndipo gawo lina zikubweretsa mapangidwe zilonda zotupa.

Cell-mkhalapakati chitetezo chokwanira. Zimene chitetezo cha m'thupi ndi kuwalimbikitsa aliyense, kutchedwa ayankhe m'thupi limene chitetezo si mtsikana ndi zovuta ya mapuloteni pano mu magazi (womuyenerera dongosolo), otchedwa ndi mawu akuti "chitetezo chokwanira ma". Iwo makamaka ndi tizilombo kupulumuka mu phagocytes ndipo ndi tizilombo kuti kupatsira maselo ena. Makamaka ndi ogwira tizilombo, bowa, mogwirizana, mabakiteriya ndi maselo chotupa. ma chitetezo ndi zofunika kwambiri minofu kukanidwa.

Mpanda selo. The okhwima khoma selo, anaikidwa kunja kwa nembanemba cytoplasmic kuti amachita chitetezo structural ndi zoyendera ntchito - ndi selo nembanemba. Koma iwo akutchedwa khoma khungu, kuti alipo ambiri mabakiteriya, nkhungu, zomera ndi archaea. Monga nyama, ndi zambiri zosavuta, iwo alibe mpanda selo.