The katal (symbol: kat) is the SI unit of catalytic activity. It quantifies the rate at which a catalyst (such as an enzyme) converts reactants in a chemical reaction. Specifically, one katal represents the catalytic activity that raises the rate of conversion by one mole per second in a specified assay system.

Key points

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  • Definition: One katal refers to an amount of enzyme that gives a catalysed rate of conversion of one mole per second.
  • Practical Use: Since the katal is quite large for most enzymatic reactions, the nanokatal (nkat) is commonly used in practice.
  • SI Multiples: The katal has various SI multiples, ranging from femtokatal (fkat) to megakatal (Mkat), depending on the scale of catalytic activity.