Question

Let’s consider an electrical current through a single ion channel, as shown in the following figure. We start by treating an ion channel as a cylindrical pore through the cell membrane. The channel is of length L ≈ 5 nm and is filled with water. The concentration difference of Na+ ions across the channel is Δc ≈ 100 mM. This concentration difference produces a flux of ions
through the channel given by DΔc/L, where D is the diffusion constant for ions in water. For small ions, like Na+, the diffusion constant in water is of the order of 1 μm2

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Answer #1

it is for the fact, tfat current is flow of changes per second.then we see that a current of about one pA corresponds to roughly 10^(7) ions passing through the channel each second.

characteristic rate of ions passing through channel C 1 ion charge characteristic current 1 pA= 10-12 1.6x 1019「~ 107 10ns

B):we find it matches with experimental values

Estimating the characteristic current flowing through an ion channel out We use Fick's Law for the flux: J,--p3C D A linear profile of concentration satisfies the steady-state diffusion equation c(z) = cout-(Cout-Cin) Z OZ number ; current is JxAs J x π r2-D Δ8mr2 in Units of flux are area xs 2 D 1000 for ions Membrane thickness, L 4nm Channel radius, r 1nm For ions characteristic Δε 10mM 107/um3 2 7tr 2 Hm

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Let’s consider an electrical current through a single ion channel, as shown in the following figure. We start by treating an ion channel as a cylindrical pore through the cell membrane. The channel is...

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Answer 1

it is for the fact, tfat current is flow of changes per second.then we see that a current of about one pA corresponds to roughly 10^(7) ions passing through the channel each second.

characteristic rate of ions passing through channel C 1 ion charge characteristic current 1 pA= 10-12 1.6x 1019「~ 107 10ns

B):we find it matches with experimental values

Estimating the characteristic current flowing through an ion channel out We use Fick's Law for the flux: J,--p3C D A linear profile of concentration satisfies the steady-state diffusion equation c(z) = cout-(Cout-Cin) Z OZ number ; current is JxAs J x π r2-D Δ8mr2 in Units of flux are area xs 2 D 1000 for ions Membrane thickness, L 4nm Channel radius, r 1nm For ions characteristic Δε 10mM 107/um3 2 7tr 2 Hm