Chemical kinetics is one of the oldest disciplines of physical chemistry, and it is fundamentally concerned with understanding mechanisms and assigning precise rate constants to certain mechanistic stages. Kinetics is an inextricably linked study of dynamics, mechanism, and electrical structure. It describes the rate at which chemical species transform their molecular bonds to generate new compounds.
Catalytic activity is defined as the increase in the rate of a specific chemical reaction mediated by an enzyme or other catalyst. It is expressed in either katals or moles per second. Catalytic activity is currently measured using spectrophotometry, colorimetry (photometry), manometry, potentiometry, and polarography.