autocatalitik

Autocatalitik, or autocatalysis, describes a chemical process in which a product of the reaction acts as a catalyst for the same reaction, accelerating its own formation. This creates a positive feedback loop: as more product forms, the reaction rate increases, often changing how fast the reactants are consumed.

In many autocatalytic systems the kinetics show a characteristic lag followed by rapid acceleration, producing a sigmoidal (S-shaped) curve in batch experiments. The mechanism can involve the product stabilizing an active catalytic site, altering the reaction environment, or participating in a catalytic cycle that regenerates itself. Autocatalysis can occur in simple reactions and also within larger networks where multiple species mutually promote each other’s production.

A classic laboratory example is the bromate-bromide reaction in acidic solution, where bromine species produced during the reaction catalyze further steps that generate more bromine. This creates a self-accelerating progression of the reaction. More complex autocatalytic behavior is studied in oscillating reactions such as the Belousov–Zhabotinsky reaction, where autocatalytic steps contribute to rhythmic changes in color and composition.

Beyond individual reactions, the concept extends to autocatalytic sets in systems chemistry and origin-of-life research. An autocatalytic set consists of molecules that collectively catalyze each other’s formation, enabling self-sustaining networks. Such ideas help explain how simple chemical systems could become more organized and capable of growth under the right conditions.

Autocatalitik is a fundamental mechanism in chemistry and beyond, illustrating how self-organization can emerge from feedback between product formation and catalytic activity.