A single
chemical reaction is said to have undergone
autocatalysis, or be
autocatalytic, if the reaction product itself is the
catalyst for that reaction.
A
set of chemical reactions can be said to be "collectively autocatalytic" if a number of those reactions produce, as reaction products, catalysts for enough of the other reactions that the entire set of chemical reactions is self-sustaining given an input of energy and food molecules (see
autocatalytic set).