Life at the Cell and Below-Cell Level. The Hidden History of a Fundamental Revolution in Biology
"Dr. Ling is one of the most inventive biochemist I have ever met." |
Chapter 2. The Same Mistake Repeated in Cell Physiology (p. 8-9) |
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Thus far, we have been discussing the
structure or anatomy of the living cell. As already mentioned, the science
describing how cells function is cell physiology. The understanding of
cell physiology rests upon the understanding of cell anatomy. Obviously,
a sound cell physiology cannot be built upon an unsound cell anatomy. Under ideal conditions, cell physiological studies
should begin after the anatomy of a typical living cell has been fully
and accurately grasped. In reality, the studies of cell physiology began long
before the recognition that a typical living cell is solid. Not
surprisingly, the appeal of mature plant cells, which had captivated the early
cell anatomists, was not lost on the early cell physiologists. Like the early
cell anatomists, the early cell physiologists also made the mistake of
generalizing what they discovered in the atypical mature plant cell as typical
of all living cells. From such a viewpoint, a fluid-filled pig's bladder like
the one described next could be seen as a model of all living cells. Abbé Nollet (1700-1770),
Preceptor in the Natural Philosophy to His Majesty Louis XV of France, and the
scientific opponent of Benjamin Franklin (1706-1790) on electricity, was the
first to record in 1748 an experiment on osmosis—even though the term,
osmosis, was not yet invented (see below). Nollet
immersed in water a pig's bladder filled with water and (grain) alcohol. He
discovered that water moved across the bladder wall to the inside of the
bladder containing both water and alcohol, but alcohol did not move to the
outside containing only water.13 ð 651 Nollet thus discovered an unusual
attribute of the bladder wall—an attribute later given the name semipermeability
by van't Hoff (1826-1894).14 Nollet's discovery also set the stage for the fateful study
of artificial membranes of Moritz Traube. However,
neither Nollet's work just described nor that of Traube to be described in the chapter immediately following
involved living cells.
Two early physiological investigators of
the real living cell were René J. H. Dutrochet(1776-1847)3
pp l84-188 and Wilhelm Pfeffer (1845-1920).15
pp 10-11 They too were botanists.
And they too worked primarily with mature plant cells. Like Jean Baptiste Lamarck (1744-1829)308
and Lorenz Oken (1779-1851),5 Dutrochet had also espoused the idea that cells are
the basic units of life—all before Theodor Schwann's definitive study leading to the same
identification {and that of Matthias Schleiden
(1804-1881)3 pp l88-189}. Dutrochet believed that life is movement and
its cessation, death. And he studied the movements of water in and out
of mature plant cells and called them respectively endosmosis and exosmosis.16 Later, the prefixes were
dropped. Spontaneous movement of water in and out of solutions or living cells
has been referred to ever since as osmosis. As mentioned, the microanatomists
had rather quickly discovered and corrected the error in describing a typical
living cell as a fluid-filled chamber. The early cell physiologists did not
make a quick correction on their own; nor did they
respond to the revised view of the microanatomists.
The same mistake committed by early microanatomists
was repeated by the cell physiologists. Only this time, the mistake has endured
to this very day. Under the banner of the membrane theory, or the
modified version called the membrane-pump theory, the typical living
cell is once again a membrane-enclosed dilute solution. |
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