Hydrolysis, enzymatic

Enzymatic fat splitting Enzymatic hydrolysis Enzymatic methods Enzymatic oxidation Enzymatic resolutions... 

The degradation of agrochemicals during storage may result from a variety of factors such as acidic and alkaline hydrolysis, enzymatic action, etc. It is recommended that a preliminary stability study be performed for the chemical in the environmental sample. If the chemical is stable under acidic conditions, for example, samples can be stored after acidification with hydrochloric or phosphoric acid. 

The toxicity of the P-halidc anhydrides, like that of phosphoroxychloride (POCl3) and of other organophosphorus compounds discussed earlier in this section, is due to their high efficiency as irreversible inactivators of acetylcholinesterase [157]. The main target organs for the lethal effects of these chemical weapons are the brain and diaphragm. As for the detoxification of the P-halide anhydrides, it can occur by a number of biochemical mechanisms, namely chemical hydrolysis, enzymatic hydrolysis, and binding to hydrolases such as carboxylesterases, cholinesterases, and albumin [68][158][159]. 

Enzymatic Hydrolysis. Enzymatic hydrolysis has received enormous attention. The enzymes generally employed are lipases from microorgan isms, plants, or mammalian liver. The great advantage of the enzymatic process is its high chemo- and stereoselectivity. 

Methods of extracting the fat-soluble vitamin from food matrices include alkaline hydrolysis, enzymatic hydrolysis, alcoholysis, direct solvent extraction, and supercritical fluid extraction of the total lipid component. 

Figure 10. Data on the heterogeneous acid hydrolysis, enzymatic hydrolysis, and photochemical decomposition of regenerated cellulose. (Reproduced with permission from Ref. 16. Copyright 1966 TAPPI.)...

Technically, acid hydrolysis is often preferred (except for acid-labile hormones), because the process offers simplicity and speed and usually results in complete hydrolysis regardless of the nature of conjugates. Enzymatic hydrolysis requires special attention to factors such as optimal concentration and type of enzyme, pH, temperature, and duration of incubation. In addition, the possible presence of enzyme inhibitors, which vary in amount and nature with different specimens, may affect the completeness of hydrolysis. In spite of potential problems, enzymatic hydrolysis is used for plasma analysis of steroids that are labile in strong acid solution (e.g., pregnanetriol and corticosteroids), and because it prevents interference from substances that are produced by acid hydrolysis. Enzymatic hydrolysis, for example, has been used successfully to determme the urine concentration of estrone and the plasma concentration of estrone sulfate in postmenopausal women. 

The in vivo stability of a natural polyelectrolyte complex membrane, such as is formed between alginate and polylysine, (or even between synthetic polyelectrolytes) must never be assumed due to slow site-by-site displacement reactions which may occur with high molecular weight polymers (proteins, etc.) present in body fluids, and to processes of hydrolysis, enzymatically promoted or otherwise which may disrupt the membrane. 

The many circumstances leading to the Henri equation for enzyme conversion of soluble substrates are first noted, followed by some kinetic forms for particulate and polymer hydrolysis. Effects common to immobilized enzyme systems are summarized. Illustrative applications discussed Include metabolic kinetics, lipid hydrolysis, enzymatic cell lysis, starch liquefaction, microenvironment influences, colloidal forces, and enzyme deactivation, all topics of interest to the larger themes of kinetics and thermodynamics of microbial systems. 

Detection After alkaline hydrolysis, enzymatically ly means of [ P]ATP and choline kinase (EC 2.7.1.32). Lit Biochem. Soc. Trans. 17, 76-79 (1989). Bergmeyer, Methods of Enzymatic Analysis (3.), vol. 8, p. 462-473, Wein-heim Verl. Chemie 1985. 

Comparing variable Dilute-acid hydrolysis Enzymatic hydrolysis... 

The solid liquid te., S L) path denotes a general route of converting biomass solids directly into liquid-state small molecules, usually called bio-oil. The bio-oil is then upgraded to generate high-quality liquid fuels. Approaehes following the S L path inelude pyrolysis, liquefaction, chemical hydrolysis, enzymatic hydrolysis, and methanol-phase reforming. 

Dennhart, N. and T. Letzel. 2006. Mass spectrometric real-time monitoring of enzymatic glycosidic hydrolysis, enzymatic inhibition and enzyme complexes. Anal. Bioanal. Chem. 386 689-698. 

Biological samples The dangers of oxidation, hydrolysis, enzymatic or bacterial transformation, and photodecomposition are usually greater with organic analytes than inorganic ones. The effects are usually concentration dependent that can add to the difficulties of the analysis. With analytes in biological samples they are usually stored at low temperatures to slow down the kinetics of the alteration processes. 

In addition to solubilization and hydrolysis, enzymatic degradation is also a very common degradation mechanism. The enzymatic degradation can act on... 

Fission of long chains occurs because of hydrolysis, enzymatic attack, or both. 

Degradation can occur via hydrolysis, enzymatic hydrolysis, photolytic cleavage, or a combination of these mechanisms and, depending on the appUcation, it can be controlled by mechanical properties and the cross-Unking density. 

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