precursor


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precursor

 [pre-ker´ser]
something that precedes. In biological processes, a substance from which another, usually more active or mature substance, is formed. In clinical medicine, a sign or symptom that heralds another.

pre·cur·sor

(prē-kŭr'sŏr),
That which precedes another or from which another is derived, applied especially to a physiologically inactive substance that is converted to an active enzyme, vitamin, hormone, etc., or to a chemical substance that is built into a larger structure in the course of synthesizing the latter.
[L. praecursor, fr. prae-, pre- + curro, to run]

precursor

/pre·cur·sor/ (pre´kur-ser) something that precedes. In biological processes, a substance from which another, usually more active or mature, substance is formed. In clinical medicine, a sign or symptom that heralds another.precur´sory

precursor

(prĭ-kûr′sər, prē′kûr′sər)
n.
A biochemical substance, such as an intermediate compound in a chain of enzymatic reactions, from which a more stable or definitive product is formed: a precursor of insulin.

precursor

[-kur′sər]
Etymology: L, prae + currere, to run
1 something preceding, or coming before, another.
2 a prognostic characteristic or feature of a patient's health data, such as a radiographic or laboratory finding, that is associated with a higher or lower risk of death than the average.

pre·cur·sor

(prē'kŭrs-ŏr)
That which precedes another or from which another is derived, applied especially to a physiologically inactive substance that is converted to an active enzyme, vitamin, or hormone, or to a chemical substance that is built into a larger structure in the course of synthesizing the latter.
[L. praecursor, fr. prae-, pre- + curro, to run]

precursor

a form that precedes another. For example:
  1. (a) a substance that precedes and is involved in the synthesis of a compound, such as any of the intermediates in the synthesis of an AMINO ACID.
  2. (b) a cell from which other cells develop.
  3. (c) a molecule that is subjected to modification to provide an active molecule, such as the enzymic cleavage of TRYPSINOGEN to yield TRYPSIN (see ZYMOGEN).

precursor

physiologically inactive substance that converts to active form, e.g. provitamin; prohormone

pre·cur·sor

(prē'kŭrs-ŏr)
That which precedes another or from which another is derived.
[L. praecursor, fr. prae-, pre- + curro, to run]

precursor

something that precedes. In biological processes, a substance from which another, usually more active or mature substance is formed. In clinical medicine, a clinical sign or syndrome that heralds another.

precursor fragments
References in classic literature ?
Claypole thought must be the immediate precursor of a violent fit of crying.
But he had no opportunity of pondering over his love just then, for Bob Sawyer's return was the immediate precursor of the arrival of a meat-pie from the baker's, of which that gentleman insisted on his staying to partake.
One day, taking a pair of shoes to be mended, he saw the cobbler's wife seated by the fire, suffering from the terrible symptoms of heart-disease and dropsy, which he had witnessed as the precursors of his mother's death.
The mediaeval burgesses and the small peasant proprietors were the precursors of the modern bourgeoisie.
During this time, the jeweller made the diamond play and sparkle in the lamplight, and the gem threw out jets of light which made him unmindful of those which -- precursors of the storm -- began to play in at the windows.
Curious to discover of what strange events these novel sounds might be the precursors, and not a little desirous to catch a sight of the instruments which produced the terrific noise, I accompanied the natives as soon as they were in readiness to depart for the Taboo Groves.
These two pursuits have thus in a manner been the pioneers and precursors of civilization.
The followers of Chaucer, and the precursors of Shakespeare, are alike real persons to him--old Langland reminding him of Carlyle's "Gospel of Labour.
All were apprehensive of worse to come, and this was especially true of the seamen who recalled all sorts of terrible omens and warnings that had occurred during the early part of the voyage, and which they could now clearly translate into the precursors of some grim and terrible tragedy to come.
In almost all climes the tortoise and the frog are among the precursors and heralds of this season, and birds fly with song and glancing plumage, and plants spring and bloom, and winds blow, to correct this slight oscillation of the poles and preserve the equilibrium of nature.
In "Ecco Homo" he is careful to enlighten us concerning the precursors and prerequisites to the advent of this highest type, in referring to a certain passage in the "Gay Science":--
However, PAN precursor fiber is the most suitable precursor for producing high-performance carbon fiber generally because of its relatively well balanced mechanical properties and greater carbon yield(>50% of the original precursor mass) [3-5].