Page 80 - The Miracle in the Cell Membrane

The Miracle in the Cell Membrane

. . . the sta tis ti cal impos si bil i ty of liv ing struc tures emerg ing
as the result of chance is a rath er con tem po ra ry exam ple of the
much-loved and present-day level of sci en tif ic devel op ment.
Looking at the extraor di na ry pecu li ar i ties of the for ma tion of
a sin gle pro tein mol e cule that per forms bio log i cal proc ess es, it
appears impos si ble to account for these com bin ing togeth er, in
the cor rect and req ui site sequence, in the cor rect loca tion and
with the cor rect elec tri cal and mechan i cal prop er ties in terms
of a series of indi vid u al coin ci den ces. 28

All types of lip ids con tain long hydro pho bic chains of
car bon and hydro gen atoms, and these chains are either
insol u ble or only very min i mal ly sol u ble in water. The
fact that many vari e ties of lipid are insol u ble in water is
of vital bio log i cal impor tance. Were there no insol u ble
com pounds, it would be impos si ble for a cell to be divis -
i ble into sec tions and for its com po nents to remain per -
ma nent. That would be unsuit a ble for life. In a sim i lar
way, if water were a uni ver sal sol vent, then no envi ron -
ment suit ed to life could exist: It would be impos si ble for
the cell to be divid ed into com part ments or to form dura -
ble struc tures. All cell com pounds would com min gle or
melt away and dis ap pear.
In most lip ids in the cell, the length of the hydro car -
bon chain is gen er al ly 16 to 18 car bon atoms. This length
is ideal for sev er al rea sons. In terms of bio log i cal effi cien -
cy, chains longer than 18 car bon atoms are insol u ble and
can not react in water. Those short er than 16 car bon atoms
are too sol u ble. At the tem per a tures at which met a bol ic
proc ess es in liv ing things are car ried out, lip ids com -
posed of chains of this ideal length are either liq uid or in

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