Units of catalytic-activity (Enzyme activity)

by | Feb 6, 2020 | NPU Concept model, International System of Units

Units of  catalytic-activity (Enzyme Activity)

Definition Amount of enzyme that catalyses the transformation of certain moles of substrate per time unit under standard conditions (ref. 1)
Scope Two corresponding units to catalytic-activity (enzyme activity) exist
Recommendation Katal is the recommended unit for catalytic-activity kind-of-quantity (ref. 2)
Reference
  1. Ferard G, Dybkaer R, Fuentes-Arderiu X. Compendium of Terminology and Nomenclature of Properties in Clinical Laboratory Sciences : Recommendations 2016. 1 ed: Royal Society of Chemistry; 2016. 182 p. doi:10.1039/9781782622451.
  2. Units of Enzyme Activity. European Journal of Biochemistry. 1979;97(2):319-20.https://doi.org/10.1111/j.1432-1033.1979.tb13116.x
Symbol Kat
Definition

The amount of enzyme that catalyses the transformation of one mole of substrate per second under standard conditions

kat=mol/s
Recommendation Recommended unit for use of catalytic-activity kind-of-quantity
Reference
  1. Ferard G, Dybkaer R, Fuentes-Arderiu X. Compendium of Terminology and Nomenclature of Properties in Clinical Laboratory Sciences : Recommendations 2016. 1 ed: Royal Society of Chemistry; 2016. 182 p. doi:10.1039/9781782622451.
  2. Units of Enzyme Activity. European Journal of Biochemistry. 1979;97(2):319-20.https://doi.org/10.1111/j.1432-1033.1979.tb13116.x
Symbol U
Definition

The amount of enzyme that catalyses the transformation of one micromol of substrate per minute under standard conditions

U=µmol/min
Scope Unit for use of catalytic-activity kind-of-quantity
Caution Due to the symbol, U, the symbol can be mistaken by International Unit (IU) that is a non-SI unit
Non-recommended term International Unit (IU)
Reference
  1. Ferard G, Dybkaer R, Fuentes-Arderiu X. Compendium of Terminology and Nomenclature of Properties in Clinical Laboratory Sciences : Recommendations 2016. 1 ed: Royal Society of Chemistry; 2016. 182 p. doi:10.1039/9781782622451.
  2. Units of Enzyme Activity. European Journal of Biochemistry. 1979;97(2):319-20.https://doi.org/10.1111/j.1432-1033.1979.tb13116.x