Search results
Results from the WOW.Com Content Network
In biology and biochemistry, the active site is the region of an enzyme where substrate molecules bind and undergo a chemical reaction. The active site consists of amino acid residues that form temporary bonds with the substrate, the binding site, and residues that catalyse a reaction of that substrate, the catalytic site.
The catalytic site and binding site together compose the enzyme's active site. The remaining majority of the enzyme structure serves to maintain the precise orientation and dynamics of the active site. [30] In some enzymes, no amino acids are directly involved in catalysis; instead, the enzyme contains sites to bind and orient catalytic ...
In enzymology, the turnover number (k cat) is defined as the limiting number of chemical conversions of substrate molecules per second that a single active site will execute for a given enzyme concentration [E T] for enzymes with two or more active sites. [1] For enzymes with a single active site, k cat is referred to as the catalytic constant ...
The enzyme of high energy content may firstly transfer some specific energetic group X 1 from catalytic site of the enzyme to the final place of the first bound reactant, then another group X 2 from the second bound reactant (or from the second group of the single reactant) must be transferred to active site to finish substrate conversion to ...
Glucose binds to hexokinase in the active site at the beginning of glycolysis. In biochemistry and molecular biology, a binding site is a region on a macromolecule such as a protein that binds to another molecule with specificity. [1] The binding partner of the macromolecule is often referred to as a ligand. [2]
Additionally, an alternative transferase mechanism has been evolved by amidophosphoribosyltransferase, which has two active sites. [k] In the first active site, a cysteine triad hydrolyses a glutamine substrate to release free ammonia. The ammonia then diffuses though an internal tunnel in the enzyme to the second active site, where it is ...
RuBisCO is important biologically because it catalyzes the primary chemical reaction by which inorganic carbon enters the biosphere.While many autotrophic bacteria and archaea fix carbon via the reductive acetyl CoA pathway, the 3-hydroxypropionate cycle, or the reverse Krebs cycle, these pathways are relatively small contributors to global carbon fixation compared to that catalyzed by RuBisCO.
The active site of the Cre enzyme consists of the conserved catalytic triad residues Arg 173, His 289, Arg 292 as well as the conserved nucleophilic residues Tyr 324 and Trp 315. Unlike some recombinase enzymes such as Flp recombinase, Cre does not form a shared active site between separate subunits and all the residues that contribute to the ...