Qhov sib txawv tseem ceeb ntawm actin thiab myosin yog tias actin muaj nyob hauv nyias, luv filaments thaum myosin muaj tuab, ntev filaments nyob rau hauv myofibrils ntawm cov nqaij fibers.
Actin-myosin contractile system yog lub hauv paus kev cog lus ntawm tag nrho cov leeg nqaij, thiab nws ua haujlwm raws li kev sib cuam tshuam ntawm ob cov proteins - cov actin thiab myosin. Tsis tas li ntawd, ob cov proteins no muaj nyob hauv cov leeg nqaij, thiab lawv lub koom haum feem ntau yog lub luag haujlwm rau cov leeg nqaij.
Actin yog dab tsi?
Actin yog cov protein ntau tshaj plaws hauv cov leeg nqaij, thiab nws yog lub luag haujlwm rau cov leeg nqaij. Nws tuaj yeem muaj nyob hauv ob hom sib txawv hauv lub cell. Lawv yog globular actin (G-actin) lossis filamentous actin (F-actin). G-actin yog ≈43kDa protein uas tuaj yeem khi ATP thiab polymerize los tsim cov microfilaments hu ua F-actin filaments. F-actin filaments muaj qhov pom zoo (+) xaus thiab qhov tsis zoo (-) xaus. Ob qhov kawg yog qhov muaj zog heev, tab sis muaj qhov sib txawv ntawm / tawm; Kev loj hlob ntawm filaments tshwm sim feem ntau ntawm qhov kawg zoo vim nws muaj ntau dua "ntawm" tus nqi.
Daim duab 01: Actin Filaments
Actin filaments yog cov sib txuas sib txuas thiab ntim los ntawm cov proteins xws li α-actinin txhawm rau ua kom lawv cov qauv kev ncaj ncees. Lub cellular actin network tshuav nws qhov muaj zog heev rau cov actin-interacting proteins uas pab txhawb nws kev sib dhos, ruaj khov, thiab disassembly.
Myosin yog dab tsi?
Myosins yog tsev neeg ntawm cov proteins uas cuam tshuam nrog actin. Actin-myosin complexes tsim cov cellular zog siv hauv cell contractility thiab tsiv teb tsaws. Feem ntau ntawm myosins yog (+) kawg motors, piv txwv li, lawv txav raws actin filaments mus rau (+) kawg. Muaj ntau ntau hom myosins, thiab txhua tus koom nrog hauv cov haujlwm tshwj xeeb ntawm tes. Myosin "hnyav chains" muaj ib lossis ntau lub taub hau, caj dab, thiab tus Tsov tus tw.
Daim duab 02: Actin-Myosin
Functionally, myosins kuj ntxiv dag zog rau actin network los ntawm kev sib txuas ntawm cov actin fibers. Myosin siv ATP los tsim lub zog; Yog li, nws pib cov leeg nqaij los ntawm kev yuam nws lub taub hau mus rau actin fiber. Ib qho myosin molecule tsim txog 1.4 pN ntawm lub zog thaum nws hloov qhov kev lees paub.
Dab tsi zoo sib xws ntawm Actin thiab Myosin?
- Actin thiab myosin yog ob yam proteins uas twb muaj lawm ua filaments.
- Lawv muaj nyob rau hauv cov leeg nqaij.
- Tsis tas li, cov leeg nqaij yog qhov tshwm sim ntawm kev sib cuam tshuam ntawm actin thiab myosin thiab lawv cov koom haum.
- Dhau li ntawd, lawv tau teem caij ntev hauv myofibrils.
Qhov txawv ntawm Actin thiab Myosin yog dab tsi?
Actin filaments yog nyias, luv filaments, thiab myosin filaments yog tuab, ntev filaments. Yog li, peb tuaj yeem coj qhov no los ua qhov sib txawv tseem ceeb ntawm actin thiab myosin. Tsis tas li ntawd, actin filaments tshwm sim nyob rau hauv ob hom: monomeric G-actin thiab polymeric F-actin. Whereas, myosin molecule muaj ob yam: tus Tsov tus tw thiab lub taub hau. Tus Tsov tus tw yog tsim los ntawm hnyav meromyosin (H-MM) thaum lub taub hau yog tsim los ntawm lub teeb meromyosin (L-MM). Yog li, qhov no yog lwm qhov sib txawv ntawm actin thiab myosin.
Ntxiv mus, qhov sib txawv ntxiv ntawm actin thiab myosin yog tias cov actin tsim ob qho tib si A thiab kuv bands thaum myosin tsuas yog A bands (A-band ua rau tsaus nti anisotropic band ntawm myofibril, thiab I-band tsim lub teeb isotropic. myofibril). Tsis tas li ntawd, ATP tsuas khi rau myosin 'lub taub hau', thiab nws tsis khi rau actin. Tsis tas li ntawd, tsis zoo li actin, myosin tsim lub zog los ntawm kev khi ATP txhawm rau txhawm rau pib cov leeg nqaij. Li no, qhov no kuj yog qhov txawv ntawm actin thiab myosin.
Hauv qab infographic ntawm qhov sib txawv ntawm actin thiab myosin muab ntau qhov sib txawv ntawm ob qho tib si sib piv.
Summary – Actin vs Myosin
Actin thiab myosin yog ob hom proteins uas muaj nyob hauv cov leeg nqaij. Actin ua rau nyias thiab luv filaments nyob rau hauv myofibrils thaum myosin ua tuab thiab ntev filaments. Ob hom protein filaments yog lub luag haujlwm rau cov leeg nqaij thiab txav. Lawv cuam tshuam nrog ib leeg thiab pab hauv cov leeg nqaij. Tsis tas li ntawd, muaj kev sib piv ntau dua actin filaments tam sim no hauv cov leeg nqaij. Tsis tas li ntawd, actin filaments koom nrog Z kab thiab xaub mus rau H aav, tsis zoo li myosin filaments. Txawm li cas los xij, myosin filaments tsim cov choj hla, tsis zoo li actin filaments. Yog li, qhov no qhia txog qhov sib txawv ntawm actin thiab myosin.
