n.
An SI unit of catalytic activity, measured in moles per second. One katal is the catalytic activity that raises the rate of a chemical reaction by one mole per second.
[Greek katal(usis), dissolution. See catalysis.]
katal
| Dictionary: kat·al |
(kăt'l)
n.
An SI unit of catalytic activity, measured in moles per second. One katal is the catalytic activity that raises the rate of a chemical reaction by one mole per second.
n.
An SI unit of catalytic activity, measured in moles per second. One katal is the catalytic activity that raises the rate of a chemical reaction by one mole per second.
| 5min Related Video: katal |
| Measures and Units: katal |
catalytic activity. Symbol kat. SI 2000 mol·s-1. (Previously sometimes catal.
[Dybkær R., Jørgensen K. Quantities and Units in Clinical Chemistry (Baltimore: Williams and Wilkins, 1967)])
| 1999 | 13th CGPM: ‘considering |
| • the importance for human health and safety of facilitating the use of SI units in the fields of medicine and biology, | |
| • that a non-SI unit called “unit”, symbol U, equal to 1 μmol·min-1, which is not coherent with the SI, has been in widespread use in medicine and biochemistry since 1964 for expressing catalytic activity, | |
| • that the absence of a special name for the SI coherent derived unit of mole per second has led to results of clinical measurements being given in various local units, that the use of SI units in medicine and clinical chemistry is strongly recommended by the international unions in these fields, | |
| • that the International Federation of Clinical Chemistry and Laboratory Medicine has asked the Consultative Committee for Units to recommend the special name katal, symbol kat, for the SI unit mole per second, | |
| • that while the proliferation of special names represents a danger for the SI, exceptions are made related to human health and safety (15th General Conference, 1975, Resolutions 8 and 9, 16th General Conference, 1979, Resolution 5)’. | |
| noting that the name katal, symbol kat, has been used for the SI unit mole per second for over thirty years to express catalytic activity, | |
| decides to adopt the special name katal, symbol kat, for the SI unit mole per second to express catalytic activity, especially in the fields of medicine and biochemistry, | |
| and recommends that when the katal is used, the measurand be specified by reference to the measurement procedure; the measurement procedure must identify the indicator reaction.see note below |
[
| Medical Dictionary: kat·al |
| Veterinary Dictionary: katal |
The SI unit of measurement to express activities of all catalysts, including enzymes, being that amount of a catalyst that catalyzes a reaction rate of 1 mole of substrate per second. Symbol kat.
| Wikipedia: Katal |
The katal (symbol: kat) is the SI unit of catalytic activity.[1] It is a derived SI unit for expressing quantity values of catalytic activity of enzymes and other catalysts. Its use is recommended by the General Conference on Weights and Measures and other international organizations. It replaces the non-SI enzyme unit. Enzyme units are, however, still more commonly used than the katal in practice at present, especially in biochemistry.
The katal is not used to express the rate of a reaction; that is expressed in moles per second. Rather, it is used to express catalytic activity which is a property of the catalyst. The katal is invariant of the measurement procedure, but the numerical quantity value is not and depends on the experimental conditions. Therefore, in order to define the quantity of a catalyst, the rate of conversion of a defined chemical reaction has to be specified, preferably of the first order, under strictly controlled conditions. One katal of trypsin, for example, is that amount of trypsin which breaks a mole of peptide bonds per second under specified conditions.
Contents |
Definition
SI multiples
| Submultiples | Multiples | |||||
|---|---|---|---|---|---|---|
| Value | Symbol | Name | Value | Symbol | Name | |
| 10–1 kat | dkat | decikatal | 101 kat | dakat | decakatal | |
| 10–2 kat | ckat | centikatal | 102 kat | hkat | hectokatal | |
| 10–3 kat | mkat | millikatal | 103 kat | kkat | kilokatal | |
| 10–6 kat | µkat | microkatal | 106 kat | Mkat | megakatal | |
| 10–9 kat | nkat | nanokatal | 109 kat | Gkat | gigakatal | |
| 10–12 kat | pkat | picokatal | 1012 kat | Tkat | terakatal | |
| 10–15 kat | fkat | femtokatal | 1015 kat | Pkat | petakatal | |
| 10–18 kat | akat | attokatal | 1018 kat | Ekat | exakatal | |
| 10–21 kat | zkat | zeptokatal | 1021 kat | Zkat | zettakatal | |
| 10–24 kat | ykat | yoctokatal | 1024 kat | Ykat | yottakatal | |
Origin
The name katal has been used for decades and it became an official SI unit in 1999.
References
External links
- Unit "katal" for catalytic activity (IUPAC Technical Report) Pure Appl. Chem. Vol. 73, No. 6, pp. 927-931 (2001) [1]
- René Dybkær (1 March 2002). "The Tortuous Road to the Adoption of katal for the Expression of Catalytic Activity by the General Conference on Weights and Measures". Clinical Chemistry 48 (3): 586–590. PMID 11861460. http://www.clinchem.org/cgi/content/full/48/3/586.
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 | Dictionary. The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved. Read more |
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| Measures and Units. A Dictionary of Weights, Measures, and Units. Copyright © Donald Fenna 2002, 2004. All rights reserved. Read more |
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| Medical Dictionary. The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Read more |
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| Veterinary Dictionary. Saunders Comprehensive Veterinary Dictionary 3rd Edition. Copyright © 2007 by D.C. Blood, V.P. Studdert and C.C. Gay, Elsevier. All rights reserved. Read more |
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| Wikipedia. This article is licensed under the Creative Commons Attribution/Share-Alike License. It uses material from the Wikipedia article "Katal". Read more |
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