The Michaelis-Menten (MM) equation is the basic equation of enzyme kinetics; it is also a basic building block of many models of biological systems. We build a stochastic and microscopic model of enzyme kinetics inside a small subcellular compartment. Using both theory and simulations, we show that intrinsic noise induces a breakdown of the MM equation even if steady-state metabolic conditions ...

The summation of the effects of two or more reversible inhibitors of various types on the initial velocity of enzyme systems obeying Michaelis-Menten kinetics is described by the the general relation: (formula: see text) wherein v1,2,3...n is the velocity of reaction in the simultaneous presence of n inhibitors, vi is the velocity observed in the presence of each individual inhibitor, and v0 is...

Abstract. Ectoenzymatic activity, prokaryotic heterotrophic abundances and production were determined in the Mediterranean Sea. Sampling was carried out sub-surface, deep chlorophyll maximum layer (DCM), core of Levantine intermediate waters deeper part mesopelagic layers. Michaelis–Menten kinetics assessed using a large range concentrations fluorogenic substrates (0.025 to 50 µM). As consequen...

A chitinase-producing bacteria was locally isolated from rhinoceros beetle (Oryctes rhinoceros) larvae gut discovered in mushroom compost. strain selected the source and labeled as RBLG1. It identified using 16s rDNAsequencing has strong homology to Bacillus cereus. Chitinase produced RBLG1 purified ammonium sulfate precipitation, ion exchange chromatography, gel filtration. The chitinase shows...

This note studies the number of positive steady states in biomolecular reactions consisting of activation/deactivation futile cycles, such as those arising from phosphorylations and dephosphorylations at each level of a MAPK cascade. It is shown that (1) for some parameter ranges, there are at least n + 1 (if n is even) or n (if n is odd) steady states; (2) There never are more than 2n steady s...

this paper investigates the importance of considering biomass growth and decay for predicting a field scale microbial degradation of btex plume in an unconfined aquifer system in the pump station area of tehran oil refinery (tor), iran. a two-dimensional finite volume model has been presented to predict multi-species reactive transport incorporating physical, chemical and biological processes i...

Methylation of mercury (Hg) is the crucial process that controls Hg biomagnification along the aquatic food chains. Aquatic sediments are of particular interest because they constitute an essential reservoir where inorganic divalent Hg (Hg II ) is methylated. Methylmercury (MeHg) concentrations in sediments mainly result from the balance between methylation and demethylation reactions, two oppo...