Page 108 - The Miracle in the Cell Membrane

The Miracle in the Cell Membrane

that con stant ly needs to be expelled—required ener gy, as
is the case with such sub stan ces as sodi um ions (Na+)
and potas si um ions (K+), then we would need an amount
of ener gy dif fi cult to express in num bers. In fact, how e -
ver, large quan ti ties of oxy gen enter the cell as if no mem -
brane were there. The way sub stan ces that the cell needs
in large quan ti ties can enter with out any ener gy expend -
i ture is just one of the signs of Allah's com pas sion for us.
The speed at which sub stan ces enter the cell is influ -
enced by the speed of motion of these sub stan ces' mol e -
cu les and the num ber of spa ces in the mem brane. At
times of urgent need, how e ver, the body is able to accel -
er ate that absorp tion by secret ing a spe cial hor mone that
wid ens the gaps between the cell mol e cu les, tak ing in as
much water and expel ling as much urea as is need ed. In
cases of urgent need, sodi um (Na+) and potas si um (K+)
ions, which enter the cell by the expend i ture of ener gy
under typical con di tions, can be taken into the cell by
means of a facil i tat ed pas sage. For exam ple, when you
acci den tal ly burn your hand, rapid com mu ni ca tion takes
place between the nerve cells. A sub stance called ace tyl -
cho line is secret ed, and a neg a tive ly charged chan nel 0.6
nanom e ters in diam e ter opens in the cell mem brane. In
this way, large mol e cu les and pos i tive ly charged ions can
eas i ly enter and leave the cell. As the door way out side
the cell opens, sodi um enters, and as the door way inside
the cell opens, potas si um exits, wait ing in the inter cel lu -
lar fluid until taken in. Thus the warn ing sig nal is trans -
mit ted from one cell to anoth er. The sig nal that goes to
the brain when you touch some thing hot returns by the

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