any of a group of compounds that are inactive precursors of enzymes and require some change (such as the hydrolysis of a fragment that masks an active enzyme) to become active
calquera elemento dun grupo de compostos que son precursores inactivos de enzimas e funciona de enzima e precisan dalgunha mudanza (como a hidrólise dun fragmento que oculta un enzima activoa) para facer activo