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Review of the Use of Tracers in the Study of Amino Acids
Dr. David Horton, A&C ATOMIC ENERGY PRCJECT,
U.C.L.A.
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In the old search for understanding of the mysteries of living organisms, the
study of amino acids and the proteins which are synthesized from them is of primary
importance four this reason:
whereas the carbohydrates and fats serve chiefly as
sources of encrgy (released in their oxidation by the organism), the proteins are
intimteiy involved in the intricate processes responsible for the integrity of the
orgeniea as a unit.
In support of this view it should be sufficient to point out that
the enzymes essential for the complex syntheses and degradations which compromise life
are all largely
protein in nature; and this is to say nothing of their important role
in issanolegical specificity, the ticed-clotting mechanism, and the structural units
Tne Zievortanes of
mul. tin axuremc comple:dty of theirs fine structure (which is germain to their many
corphex Panchiens} has meade the study of them very difficult.
Hence it wes with no
“eee of exeiterent thet students of the metzibclosm of amino acids and proteins
gromtsd vhe rotreor sudden availalility of appreciable cuantitises of isotopic forms of
cil the sicmental substences important to livine systems.
As will become apparent
in the course cf the talk, isotones cre extrenely porerful iools in the study of
metubkelic processes.
Net only can isotopes help solve problems which are very difficult
but it is apparent that many problems may now be solved which were pree-
viously imrossible of solution, without elemental substances of unnatural isotopic
composition and mans for determining this difference.
That biolegists (using the term in its broadest aspects) were awaiting just such
a tcol is attested by the exceedingly rupid growth of the number of applications of
nuclear physics to the biologicel end medical sciences.
Despite its really great
veuvh, the field has grown to a size difficult tc encompass in three weeks of courses;
end in ene heur I cannot hope to cover completely the many instences already in the
published litereture on the metabolism of the amino acids.