Enzymes, carbohydrate-hydrolyzing

The cuticle, being attached to the epidermal cells via a pectinaceous layer, can be released by disruption of this layer by chemicals such as ammonium oxalate/oxalic acid or by pectin-degrading enzymes. After treatment of the recovered cuticular layer with carbohydrate-hydrolyzing enzymes to remove the remaining attached carbohydrates, the soluble waxes can be removed by ex-... 

The carbohydrate-hydrolyzing enzymes were inhibited by fairly... 

FIGURE 2.44 Carbohydrate-hydrolyzing enzymes. Starch-hydrolyzing enzymes act prior to the oligosaccharide- and disaccharide-hydrolyzing enzymes. 

The solvent extraction can be enhanced by utilizing carbohydrate-hydrolyzing enzymes, for instance pectinase, cellulase, hemicellulase, and many other enzymes, which can be used to disintegrate the plant cell-wall matrix leading to more efficient release of phenolic compounds [36]. Enzymatic-assisted extraction has been applied for superior extraction of pol3q)henolic compounds from different biomaterials, such as black currant juice press residues [37, 38], pigeon pea leaves [39], and grape pomace [40]. 

Acid-soluble and acid-insoluble phosphates in ChloreUa vulgaris increased 2 to 4 fold, depending on the concentration of trichioroacetate, with the soluble phosphorus most affected. However, neither respiration nor the carbohydrate-metabolizing enzymes were particularly sensitive. Little change occurred in the hydrolyzable polysaccharides.168... 

The biochemical role of minerals in metabolic processes of various organisms has been covered in several reviews by Malstrom and Neilands (20A60), McElroy and Nason (20A65), Nason and McElroy (20A81), and Nicholas (20A84). The function of C, H, and O are obvious since they are constituents of fats, carbohydrates, and proteins. N and S are constituents of amino acids, proteins, coenzymes, and other compounds. Ca forms a complex with pectic acid and functions as a constituent of the middle lamella of cell walls. Dixon and Webb (20A13) showed that Ca also plays a role as a cofactor for certain adenosine triphosphate hydrolyzing enzymes, for phospholipases, and as a cofactor for the amylases from a variety of plants. Many elements, especially the cations, play essential roles as cofactors for the enzymes of various metabolic sequences. 

The isomerism existing between the pairs of nucleotides was attributed to the different locations of the phosphoryl residues in the carbohydrate part of the parent nucleoside,49 63 since, for instance, the isomeric adenylic acids are both hydrolyzed by acids to adenine, and by alkalis or kidney phosphatase to adenosine. Neither is identical with adenosine 5-phosphate since they are not deaminated by adenylic-acid deaminase,68 60 and are both more labile to acids than is muscle adenylic acid. An alternative explanation of the isomerism was put forward by Doherty.61 He was able, by a process of transglycosidation, to convert adenylic acids a" and 6 to benzyl D-riboside phosphates which were then hydrogenated to optically inactive ribitol phosphates. He concluded from this that both isomers are 3-phosphates and that the isomerism is due to different configurations at the anomeric position. This evidence is, however, open to the same criticism detailed above in connection with the work of Levene and coworkers. Further work has amply justified the original conclusion regarding the nature of the isomerism, since it has been found that, in all four cases, a and 6 isomers give rise to the same nucleoside on enzymic hydrolysis.62 62 63 It was therefore evident that the isomeric nucleotides are 2- and 3-phosphates, since they are demonstrably different from the known 5-phosphates. The decision as to which of the pair is the 2- and which the 3-phosphate proved to be a difficult one. The problem is complicated by the fact that the a and b" nucleotides are readily interconvertible.64,64... 

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