прекурсор(первичная частица; a chemical that is transformed into another compound, as in the course of a chemical reaction, and therefore precedes that compound in the synthetic pathway: Cholesterol is a precursor of testosterone. RHWD. 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. Alexander Demidov)
предшественник(молекула, преобразующаяся в процессе биохимической реакции в др. молекулу, для которой исходная молекула и является П., – напр., в реакции полимеризации дезоксирибонуклеотиды являются низкомолекулярными П ДНК, а в реакции сплайсинга молекула 45S-про-рРНК является П. для конечных молекул рРНК – 18S и 28S dimock)
предвестники бедствия, катастрофы("You don't need to go through life thinking that there's going to be an extinction-level event tomorrow," he remarked. "But there can certainly be the precursors taking place that could have a devastating effect on all of our lives."coasttocoastam.comART Vancouver)
