Video: Koj ua li cas xam cov peev xwm thim rov qab?
2024 Tus sau: Miles Stephen | [email protected]. Kawg hloov kho: 2023-12-15 23:36
rau ib tug muab ion, lub rov qab muaj peev xwm tuaj yeem xam los ntawm Nernst kev sib npaug qhov twg: R = gas tas li. T = kub (in oK) z = ion charge.
Equilibrium (los yog thim rov qab) muaj peev xwm
- ib tug so membrane peev xwm ntawm -12 mV (raws li tsim los ntawm Na+/K+ ATPase)
- tsis muaj voltage- lossis ligand-gated channels.
- thaum xub thawj, tsis muaj cov pa xau.
Ntawm no, qhov kev thim rov qab txhais tau li cas?
Nyob rau hauv ib tug bio membrane, lub rov qab muaj peev xwm (tseem hu ua Nernst peev xwm ) ib ion yog daim nyias nyias peev xwm nyob ntawd yog tsis muaj net (tag nrho) ntws ntawm qhov tshwj xeeb ion ntawm ib sab ntawm daim nyias nyias mus rau lwm qhov. Equilibrium hais txog qhov tseeb tias cov net ion flux ntawm ib qho hluav taws xob tshwj xeeb yog xoom.
Tsis tas li ntawd, qhov tsis zoo nernst muaj peev xwm txhais tau li cas? (Lub Nernst muaj peev xwm yog qhov voltage qho yuav sib npaug tawm qhov tsis sib npaug ntawm qhov sib npaug ntawm daim nyias nyias rau qhov ion. Ib tug loj tsis zoo Qhov voltage (-90mV) yuav tuav qhov zoo K + ions hauv cell. Cov kev sib tw nyiam, cov nqi zoo sib xws ua rau ib leeg).
Ib yam li ib tug yuav nug, dab tsi yog qhov sib npaug ntawm cov poov tshuaj?
Cov Potassium equilibrium muaj peev xwm E K yog −84 mV 5 mM poov tshuaj sab nraud thiab 140 mM sab hauv. Ntawm qhov tod tes, sodium equilibrium muaj peev xwm , ENa, yog kwv yees li +66 mV nrog kwv yees li 12 mM sodium sab hauv thiab 140 mM sab nraud.
Dab tsi ua rau muaj peev xwm ua tau?
Tej yam peev xwm ua tau yog ua rau thaum sib txawv ions hla lub neuron membrane. Ib qho stimulus ua ntej ua rau sodium channels qhib. Vim tias muaj ntau ntau sodium ions nyob rau sab nraud, thiab sab hauv ntawm cov neuron yog qhov tsis zoo rau sab nraud, sodium ions maj nrawm rau hauv cov neuron.
Pom zoo:
Yuav ua li cas koj xam tag nrho cov peev xwm?
Txheej Txheem Muaj Peev Xwm Lawv raug suav los ntawm cov qauv hauv qab no: Tib neeg muaj peev xwm = cov sijhawm ua haujlwm tiag tiag x tus nqi tuaj koom x tus nqi zog ncaj qha x sib npaug tib neeg lub zog. Tshuab muaj peev xwm = ua hauj lwm teev x kev khiav hauj lwm tus nqi x tus naj npawb ntawm lub tshuab
Dab tsi yog qhov txawv ntawm electrostatic muaj peev xwm thiab electrostatic muaj peev xwm zog?
Tsis muaj qhov sib txawv ntawm electrostatic potentialenergy thiab hluav taws xob (al) muaj peev xwm zog. Lub peev xwm hluav taws xob ntawm ib qho taw tes yog kev ua haujlwm los ntawm lwm qhov kev quab yuam hauv kev txav chav tsev zoo los ntawm ib qho arbitrarilychosen xoom ntawm lub peev xwm (feem ntau infinity) mus rau lub ntsiab lus
Puas muaj peev xwm hluav taws xob thiab lub zog muaj peev xwm tib yam Vim li cas lossis vim li cas ho tsis?
Lub zog muaj peev xwm hluav taws xob Ue yog lub zog muaj peev xwm khaws cia thaum cov nqi tawm ntawm qhov sib npaug (xws li lub zog muaj peev xwm gravitational). Lub peev xwm hluav taws xob zoo ib yam, tab sis ib tus nqi, Ueq. Ib qho hluav taws xob muaj peev xwm sib txawv ntawm ob lub ntsiab lus hu ua voltage, V = Ue2q−Ue1q
Koj tuaj yeem qhia tau li cas yog tias muaj kev cuam tshuam rau pem hauv ntej lossis thim rov qab?
Yog tias K K, cov reactants tau txais kev pom zoo. Yog tias Q< K, cov khoom raug nyiam
Yuav ua li cas koj xam cov elastic muaj peev xwm ntawm lub caij nplooj ntoos hlav?
Elastic muaj peev xwm zog yog sib npaug rau lub zog lub sij hawm ntawm qhov kev ncua deb ntawm kev txav mus los. Elastic muaj peev xwm zog = quab yuam x deb ntawm kev xaav. Vim tias lub zog yog = lub caij nplooj ntoos hlav tas li x hloov chaw, ces Elastic muaj peev xwm zog = lub caij nplooj ntoos hlav tas li x hloov chaw squared