ABSTRACT
Catalysts accelerate chemical reactions without affecting the equilibrium constant. According to transition state theory, catalysts accelerate chemical reactions by stabilization of the active complex, the transition state. As a consequence, the activation barrier is reduced, and the rate constant is increased. The catalyst is regenerated at the end of the reaction, meaning it is not consumed but can catalyze multiple turnovers. Biomolecules that act as catalysts include enzymes, catalytically active antibodies, and ribozymes. The stabilization of the transition state leads to a decrease in activation energy, both for the forward reaction from reactants to products and for the inverse reaction from products to reactants. Interactions of the enzyme with the substrate contribute to enzyme specificity. Acid-base catalysis involves the transfer of a proton to the reactant to stabilize negative charges in the transition state, or the abstraction of a proton to stabilize a developing positive charge.
