The mass action kinetic model of the irreversible Michael&Menten reaction mechanism is mathematically intractable: an explicit analytical solution cannot be obtained. This difficulty is overcome by applying simplifying kinetic assumptions but a full understanding of their dynamic implications and applicability is not readily available. This paper shows how simple modal analysis can provide both...

1. Methyl thionohippurate was prepared and shown to be a specific substrate for both papain and ficin. 2. The ultraviolet-absorption properties of the acyl-enzyme intermediate for both papain and ficin with methyl thionohippurate was that expected of an acyl-thiol. The possibility that other functional groups present in papain or ficin might be the site of acylation has been excluded. 3. The ch...

The conditions for the validity of standard quasi-steady-state approximation in Michaelis--Menten mechanism a closed reaction vessel have been well studied, but much less so this system with substrate inflow. We analyze scenarios open attributable to singular perturbations, as restrictive conditions. For both settings we obtain distinguished invariant slow manifolds and time scale estimates, hi...

Enzymes are dynamic entities: both their conformation and catalytic activity fluctuate over time. When such fluctuations are relatively fast, it is not surprising that the classical Michaelis-Menten (MM) relationship between the steady-state enzymatic velocity and the substrate concentration still holds. However, recent single-molecule experiments have shown that this is the case even for an en...

When the concentration dependence of an enzymic reaction or a transport process can be described by the sum of two Michaelis-Menten terms, reliable data that relate reaction rate and substrate concentration can be obtained even when as much as 70 per cent of substrate was consumed during the assay. Each data pair consists of the average reaction rate during an assay and the concentration where ...

BACKGROUND AND AIMS Previous work has shown that the entire photosynthetic light response curve, based on both Mitscherlich and Michaelis-Menten functions, could be predicted in an interspecific context through allometric relations linking the parameters of these functions to two static leaf traits: leaf nitrogen (N) content and leaf mass per area (LMA). This paper describes to what extent thes...

Morphine elimination involves UDP-glucuronosyltransferase (UGT) catalyzed conjugation with glucuronic acid to form morphine 3- and 6-glucuronides (M3G and M6G, respectively). It has been proposed that UGT2B7 is the major enzyme involved in these reactions, but there is evidence to suggest that other isoforms also catalyze morphine glucuronidation in man. Thus, we have characterized the selectiv...

A method based on the rate of depletion of a nutrient from solution was developed to characterize nutrient flux of plant roots. Nutrient concentration of the solution was measured at a series of time intervals to describe the complete depletion curve. An integrated rate equation, based on a Michaelis-Menten model, was developed and fit to the data of the depletion curve using a least-square pro...