Kapangidwe ndi Ntchito ya Cytoskeleton
Chigoba cha cytoskeleton ndi gawo lofunika kwambiri la maselo a eukaryotic, lomwe limapereka chimango cha kapangidwe kake komanso limagwira ntchito zosiyanasiyana zamakaniko. M'nkhaniyi, tifufuza mozama kapangidwe ka chigoba cha cytoskeleton, zinthu zosiyanasiyana zomwe zimapanga, komanso ntchito zenizeni zomwe chinthu chilichonse chimachita posunga kupulumuka kwa maselo.
Kapangidwe ka Cytoskeleton
Chigoba cha cytoskeleton chili ndi mitundu itatu ikuluikulu ya ulusi wa mapuloteni: ma microtubules, ma microfilaments (kapena ma actin filaments), ndi ulusi wapakati. Mtundu uliwonse wa ulusiwu uli ndi makhalidwe ndi ntchito zosiyana.
1. Ma Microtubules
Ma microtubules ndi ma cylinders aatali opangidwa ndi puloteni ya tubulin. Ali ndi mainchesi pafupifupi 25 nm ndipo amatha kukula ndikuchepa mwachangu kudzera mu njira yotchedwa microtubule dynamics. Ma microtubules nthawi zambiri amakonzedwa mozungulira malo okonzera ma microtubule (MTOC), monga centrosome m'maselo a nyama.
Ma microtubules ali ndi ntchito zingapo zofunika:
– Kuyendera M'kati mwa Maselo: Monga 'njira' yonyamulira ma organelles ndi ma vesicles mkati mwa maselo.
– Kulekanitsa kwa Chromosome: Kumapanga chipangizo cha spindle panthawi ya mitosis ndi meiosis, kuonetsetsa kuti ma chromosome amagawidwa bwino.
- Amapereka Kapangidwe ndi Chithandizo: Amapereka mawonekedwe a selo ndipo amatsimikiza polarity ya selo.
2. Tinthu tating'onoting'ono
Ma microfilaments, omwe amadziwikanso kuti actin filaments, amapangidwa ndi puloteni actin ndipo ali ndi mainchesi pafupifupi 7 nm, zomwe zimapangitsa kuti akhale ma filaments owonda kwambiri mu cytoskeleton. Ndi amphamvu kwambiri ndipo amatha kupanga polymer ndi depolymer mwachangu.
Ntchito zazikulu za microfilaments ndi izi:
– Kuyenda kwa Maselo: Kumathandizira kuyenda kwa maselo kudzera mu njira monga kuyenda kwa ameboid ndi kutalikitsa kwa pseudopodia.
- Kupindika kwa Minofu: Kumagwirizana ndi myosin kuti minofu ipangike kupindika.
– Kukhazikika kwa Kapangidwe ka Maselo: Kumathandizira kapangidwe ka microvilli pamwamba pa maselo a epithelial.
3. Ma Filamu Apakati
Ulusi wapakati uli pakati pa ma microtubules ndi ma microfilaments, makulidwe ake ndi pafupifupi 10 nm. Ndi olimba kwambiri komanso osasinthasintha kuposa mitundu ina iwiri ya ulusi. Amapangidwa ndi mapuloteni osiyanasiyana, kuphatikizapo keratin, vimentin, ndi neurofilament, kutengera mtundu wa selo.
Ntchito za ulusi wapakati zimaphatikizapo:
- Mphamvu ya Makina: Imawonjezera mphamvu yokoka m'maselo ndi minofu.
- Kusamalira Kapangidwe ka Pakati: Kumathandiza kusunga mawonekedwe ndi kukhazikika kwa pakati.
– Kupanga kwa Desmosome: Kumapereka kulumikizana kwamphamvu pakati pa maselo.
Ntchito Yonse ya Cytoskeleton
Kuphatikiza kwa mitundu itatu iyi ya ulusi kumathandiza kuti chipolopolo cha cytoskeleton chigwire ntchito zosiyanasiyana zofunika kwambiri kuti selo likhale ndi moyo komanso kuti ligwire bwino ntchito. Nazi zina mwa ntchito zazikulu za chipolopolo cha cytoskeleton chonse:
1. Kupereka Fomu ndi Chithandizo cha Kapangidwe ka Nyumba
Chigoba cha maselo chimagwira ntchito ngati chimango mkati mwa maselo, kupereka mawonekedwe ndi kukana kupsinjika kwa makina. Mwachitsanzo, maselo ofiira a magazi ali ndi mawonekedwe ofanana ndi a biconcave, omwe amatsimikiziridwa kwambiri ndi netiweki yawo ya cytoskeleton.
2. Malamulo Oyendetsera Kukhazikika kwa Maselo
Pogwiritsa ntchito zinthu za cytoskeletal, maselo amatha kuwongolera malo a ma organelles osiyanasiyana mkati mwa cytoplasm. Ma microtubules amagwira ntchito ngati 'misewu yayikulu' ya mapuloteni oyendetsa magalimoto monga kinesin ndi dynein, omwe amanyamula ma vesicles ndi ma organelles kupita kumadera osiyanasiyana a selo.
3. Kuyenda kwa Maselo
Chigoba cha cytoskeleton chimagwira ntchito yofunika kwambiri pakuyenda kwa maselo, kaya kudzera pamwamba pa chinthu chopangidwa ndi ma cell (monga pochiritsa bala) kapena kudzera mu njira yamadzimadzi (monga umuna ukusambira pogwiritsa ntchito flagella yothandizidwa ndi ma microtubules).
4. Gawo la Maselo
Pakugawikana kwa maselo, cytoskeleton imagwira ntchito yofunika kwambiri popanga mitotic spindle, yomwe imalekanitsa ma chromosome ndi mitengo yotsutsana ya selo. Tinthu tating'onoting'ono timapanganso mphete yolumikizana yomwe imathandiza selo kugawikana pawiri.
5. Kutumiza Chizindikiro
Chigoba cha cytoskeleton chimagwiranso ntchito popereka chizindikiro cha maselo. Zigawo za chigoba cha cytoskeleton zimatha kuyanjana ndi zolandirira pamwamba pa maselo ndi mapuloteni ena olumikizirana, zomwe zimathandiza kutumiza zizindikiro kuchokera pamwamba pa selo kupita ku nyukiliyasi, zomwe zimakhudza kuyambika kwa majini ndi mayankho a maselo.
Udindo wa Cytoskeleton pa Thanzi ndi Matenda
Kufunika kwa cytoskeleton kumapitirira ntchito yachibadwa ya maselo ndipo kumachitanso gawo lofunika kwambiri pa matenda a anthu. Mwachitsanzo, matenda angapo, monga matenda owononga mitsempha, amayamba chifukwa cha kusagwira bwino ntchito kwa microtubule. Matenda a Alzheimer's ndi Parkinson's ndi zitsanzo za matenda omwe mapangidwe a microtubule amasokonekera, zomwe zimapangitsa kuti mayendedwe amkati mwa maselo asokonezeke, ndipo pamapeto pake, kuwonongeka kwa mitsempha.
Khansa ndi chitsanzo china chomwe cytoskeleton imachita gawo lofunika kwambiri. Kukula ndi kufalikira kwa maselo a khansa nthawi zambiri kumagwirizanitsidwa ndi kusintha kwa microfilament ndi microtubule dynamics, zomwe zimathandiza maselo a khansa kusuntha ndi kulowa mu minofu ina.
Kuphatikiza apo, matenda a majini monga epidermolysis bullosa simplex amayamba chifukwa cha kusintha kwa majini omwe amapanga keratin, gawo lalikulu la ulusi wapakati. Kusintha kumeneku kumapangitsa kuti khungu lisamasuke komanso kuti maselo a khungu asamatuluke chifukwa cha kufooka kwa mphamvu ya maselo a khungu.
Mapeto
Chipolopolo cha cytoskeleton ndi dongosolo lovuta komanso losinthasintha la mamolekyulu, lofunikira pafupifupi mbali iliyonse ya ntchito ya maselo. Kuyambira kupereka mawonekedwe ndi kapangidwe kake, kuthandizira kuyenda, kukonza ma organelles, mpaka kutenga nawo mbali pakugawa maselo ndi kutumiza zizindikiro, chipolopolo cha cytoskeleton ndi chinthu chofunikira kwambiri mu biology ya maselo.
Kafukufuku akupitilizabe kupititsa patsogolo kumvetsetsa kwa njira ndi ntchito za zigawo za cytoskeleton, komanso udindo wawo pa thanzi ndi matenda. Kumvetsetsa bwino ntchito ya cytoskeleton kungathandize kupeza njira zatsopano zochiritsira matenda okhudzana ndi kusokonekera kwa cytoskeleton.
Motero, tingamvetse kuti cytoskeleton ndi chinthu chopangidwa ndi kapangidwe kake komanso chogwira ntchito chomwe sichimangosunga umphumphu wa maselo komanso chimalola maselo kugwira ntchito ndikusintha m'mikhalidwe yosiyanasiyana ya zamoyo.
