Page 270 - The Miracle in the Cell Membrane

The Miracle in the Cell Membrane

- The cell membrane, just 1/100,000th of a millimeter
thick, recognizes countless chemical substances in the
extra-cellular environment, and takes in only those need-
ed for continuing organelle functions and cell survive. It
possesses an extraordinary capacity for recognition.
- It is most economical. The cell never admits any
more than the amount it actually needs.
- The cell also recognizes the harmful waste products
inside it and loses no time in getting rid of them.
- An exchange of very large molecules sometimes
takes place into and outside the cell membrane. In that
case, their passage is ensured with no harm befalling the
membrane. The cell forms small sacs from its own mem-
brane, through which storage and transportation are car-
ried out. In the process known as pinocytosis, part of the
cell membrane bends inwards, and large molecules on
the outside enter this hollow. This hollow contracts
inwards, and a sac is formed that is drawn into the cell.
In a sense, the cell swallows the substances it needs.
- In the process known as exocytosis, the cell forms a
sac inside itself, fills it with waste products, then expels
this sac through the cell membrane. Substances in the sac
are thus released into the external environment.
In order for the cell membrane, consisting of fat mol-
ecules, to perform all of these processes, it must know all
the activities and developments inside the cell, produce a
list of all necessary or harmful substances, keep stocks
under control, and maintain a superior memory and
decision-making ability. In addition, it must also develop

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