Page 169 - The Miracle in the Cell Membrane

instead of in a mem brane com posed of fat. The ion chan nels,
able to dis tin guish two ions, offer a solu tion to that prob lem.
In human beings, there are nine dif fer ent chlo ride chan nels
that serve dif fer ent func tions, from salt absorp tion in the kid -
neys to mus cle con trac tion. The chlo ride ion chan nel pos sess -
es a total ly dif fer ent struc ture from that of the potas si um ion
chan nel. Meanwhile, the potas si um ion chan nel is large ly filled
with water, of a pyram i dal shape. The chlo ride chan nel has two
spa ces, each with a nar row er space in the mid dle, rath er like
an hour glass or egg-timer. Scientists have found that the pro -
tein sub-units com pris ing both chan nels are laid out in entire -
ly dif fer ent ways. In the potas si um chan nel, four pro tein sub-
units con sti tute a sin gle space. In the chlo ride ion chan nel,
each pro tein sub-unit has its own space and both halves of the
sub-units pos sess oppo site faces in a way known as two-lay -
er ed revers i ble sym me try.
Understanding this struc ture may help sci en tists under -
stand how the chan nel opens and clos es to main tain the cor -
rect ion con cen tra tion. As you saw, despite all their advanced
tech nol o gy, sci en tists have still not fully unrav eled the com -
plex proc ess es that tran spire with in their own bod ies, with in
the cell mem brane. R. MacKinnon, who stud ies the ion chan -
nels, has stat ed that these struc tures—the gate way to the
cells—have only newly begun to be under stood, and that con -
tin u ing exper i ments seek to under stand how they func tion. 3
The cell mem brane pos sess es a spe cial struc ture for
admit ting chlo ride ions. Despite all obsta cles, the cell mem -
brane is capa ble of admit ting the nec es sa ry ions. That excep -
tion al solu tion can not, of course, be the prod uct of mol e cu les
devoid of intel lect and con scious ness. The order here is a part
of the com plex sys tem that Allah has cre at ed in our cells.

1. R. Dutzler, E.B. Campbell, M. Cardene, B.T. Chait & R. Mackinnon, "X-ray struc ture of a
ClC chlo ride chan nel at 3.0 A reveals the molec u lar basis of anion select iv i ty," Nature, No.
415, 17 January 2002, pp. 287-294.
2. http://www.hhmi.org/news/mack in non5.html; "Images Reveal How Body Regulates Salt
Uptake in Cells," Howard Hughes Medical Institute News.
3. http://www.hhmi.org/news/mackinnon5.html; “Images Reveal How Body
Regulates Salt Uptake in Cells”, Howard Hughes Medical Institute News.

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