Definition Turnover Number Enzyme

The units of turn over number kcat are k c a t moles of product sec moles of enzyme or sec 1.

Definition turnover number enzyme. Turnover a dish made by folding a piece of pastry over a filling. Turnover the ratio of the number of workers that had to be replaced in a given time period to the average number of workers. The turnover number of an enzyme or the k cat is the maximal number of molecules of substrate converted to product per active site per unit time when the enzyme is saturated with substrate garrett and grisham 1999. The turnover number per mole of enzyme is a zeroorder rate constant because it does not depend on the substrate concentration.

K c a t turnover number v m a x maximum rate of reaction when all the enzyme catalytic sites are saturated with substrate and e t total enzyme concentration or concentration of total enzyme catalytic sites. Turn o ver num ber kcat the number of substrate molecules converted into product in an enzyme catalyzed reaction under saturating conditions per unit time per unit quantity of enzyme. On the other hand if your enzyme solution is pure you could use the protein concentration in your solution to. Ratio the relative magnitudes of two quantities usually expressed as a quotient 2.

The k cat for chymotrypsin for example is 100 per second. This value is calculated from the maximal velocity. Employee turnover turnover rate. Kcat is used for describing the turnover number.

For example kcat vmax etotal. The kcat km value or specificity constant of the various substrates can be compared. A single substrate reaction will undergo a bimolecular reaction wherein a substrate s and an enzyme e will react together to form a complex of enzyme substrate es. The turnover number is the maximum number of conversions which is possible for a substrate every second by an enzyme.

In enzymology turnover number also termed kcat is defined as the maximum number of chemical conversions of substrate molecules per second that a single catalytic site will execute for a given enzyme concentration displaystyle e t for enzymes with two or more active sites. Farlex partner medical dictionary farlex 2012.