Hydrolysis of sucrose, catalyzed

The hydrolysis of sucrose catalyzed by the strongly acidic cation-exchange resin Amberlite 200C in RH form was chosen as a model reaction to compare the use of stirred tank and continuous-flow reactors [47-49], Scheme 10.6. 

In application, consider the hydrolysis of sucrose catalyzed by aqueous HCl. This is a single phase reaction with no volume change experimental data are given in... 

Thus, acid-catalyzed hydrolysis of sucrose initially yields D-glucose and a fmctose oxocarbonium ion, which can react with water to form D-fructose and regenerate the H+ catalyst. As a consequence, further acid degradation of sucrose can be described by the action of acids on D-glucose and D-fructose. 

Competitive inhibition is important in biological control mechanisms for instance, if the product assumes the role of an inhibitor. The enzyme invertase catalyzes the hydrolysis of sucrose into glucose and fructose. As glucose is a competitive inhibitor, it ensures that the reaction does not proceed too far. 

The hydrolysis of sucrose (S) catalyzed by the enzyme invertase has been studied by measuring the initial rate, rPo, at a series of initial concentrations of sucrose (cSo). At a particular temperature and enzyme concentration, the following results were obtained (Chase et al., 1962) ... 

Quantitative measurements of simple and enzyme-catalyzed reaction rates were under way by the 1850s. In that year Wilhelmy derived first order equations for acid-catalyzed hydrolysis of sucrose which he could follow by the inversion of rotation of plane polarized light. Berthellot (1862) derived second-order equations for the rates of ester formation and, shortly after, Harcourt observed that rates of reaction doubled for each 10 °C rise in temperature. Guldberg and Waage (1864-67) demonstrated that the equilibrium of the reaction was affected by the concentration ) of the reacting substance(s). By 1877 Arrhenius had derived the definition of the equilbrium constant for a reaction from the rate constants of the forward and backward reactions. Ostwald in 1884 showed that sucrose and ester hydrolyses were affected by H+ concentration (pH). 

Applications of chemical kinetics to enzyme-catalyzed reactions soon followed. Because of the ease with which its progress could be monitored polarimetrically, enzyme hydrolysis of sucrose by invertase was a popular system for study. O Sullivan and Tompson (1890) concluded that the reaction obeyed the Law of Mass Action and in a paper entitled, Invertase A Contribution to the History of an Enzyme or Unorganized Ferment , they wrote [Enzymes] possess a life function without life. Is there anything [in their actions] which can be distinguished from ordinary chemical action ... 

Bioethanol can be produced from a large variety of carbohydrates with a general formula of (CHjO) . Chemical reaction is composed of enzymatic hydrolysis of sucrose followed by fermentation of simple sugars. Fermentation of sucrose is performed using commercial yeast such as Saccharomyces cerevisiae. First, invertase enzyme in the yeast catalyzes the hydrolysis of sucrose to convert it into glucose and fmctose. 

This enzyme [EC 3.2.1.26], also known as jS-D-fructofura-nosidase and saccharase, catalyzes the hydrolysis of terminal nonreducing /3-D-fructofuranoside residues in (3-D-fructofuranosides. Hence, the enzyme will also catalyze the hydrolysis of sucrose to glucose and fructose. In addition, the protein also exhibits a fructotransferase activity. See also Sucrase... 

This method was the first accurate spectroscopic method for determining chemical reaction rates. In the mid-eighteenth century, kinetic measurements of changes in the rotation of plane polarized light upon acid-catalyzed hydrolysis of sucrose led to the concept of a dynamic equilibrium. 

Similarly to the hydrolysis of sucrose, acid exchanged resins can be utilized, in one case to give 75% hydrolysis of triglycerides after six hours at 155 °C. It was shown that the Brondsted acid sites catalyze the hydrolysis reaction, which was performed in the liquid phase with continuous steam injection.The same authors reported that polystyrene sulfonic cation-exchange resin, loaded with 13% of the superacid H3M0, gave 74.5% hydrolysis of palm oil at 155 °C in a batch reactor also operated with steam injection. 

Arsenate similarly replaces phosphate in various phosphorolysis reactions, so that sucrose phosphorylase catalyzes the hydrolysis of sucrose in its presence (23), potato phosphorylase can hydrolyze amylose and amylopectin (24), nucleoside phosphorylase can hydrolyze inosine... 

The enzyme invertase catalyzes the hydrolysis of sucrose to glucose and fructose. The rate of this enzymatic reaction decreases at higher substrate concentrations. Using the same amount of invertase, the initial rates at different sucrose concentrations are given in Table P3.9. 

A quinone-dependent sugar oxidoreductase, purified from Agaricus bisporus, catalyzes C-2 and C-3 oxidation of D-glucose to o-arabino-hexos-2-ulose and preferentially to D-n fto-hexos-3-ulosc. The two aldoketoses accumulate transiently in the reaction mixture, being converted into the same end-product, D-eryt/zro-hexos-2,3-diulose. D-Galactose is oxidized exclusively at C-2 to produce D - /y.w - h c x o s - 2 - u 1 o s c.447 Fukui and Hochster448 prepared n-/vAo-hexos-3-ulose (219) by enzymic oxidation and hydrolysis of sucrose. 

Invertase (EC 3.2.1.26) catalyzes the hydrolysis of P-fructofuranosides and has been used in analytical chemistry (biosensors), in confectionary, and in the production of inverted syrup (1). Invert sugar syrup, which can be obtained by acid or enzymatic hydrolysis of sucrose, is a valuable commercial product especially in countries where the main sources of sugar are beet or cane. With acid hydrolysis, the final syrup is often contaminated with colored oxidation compounds, which arise from cyclization of hex-oses at low pH and high temperatures (2-4). Such a problem does not occur... 

An enzyme known as invertase catalyzes the hydrolysis of sucrose to an equimolar mixture of D-glucose and D-fructose. During the hydrolysis, the optical rotation of the solution changes from (+) to (-). What can you conclude from this observation ... 

Sucrase catalyzes the hydrolysis of sucrose to glucose and fructose. Lactase catalyzes the hydrolysis of lactose to glucose and galactose. 

Painter and Morgan used poly(styrenesulfonic acid) 2 as catalyst for the selective hydrolysis of polysaccharides (JS). The pdymer add was up to twenty to thirty times more effective than hydrochloric acid in the case of polysaccharides containing free amino groups, but it was 30% less effective for the hydrolysis of unsubstituted starch 26. Obviously, the electrostatic attraction between the polymer and substrate enhanced the catalytic activity. More recently, Tal da reported that amydose sulfate catalyzed the hydrolysis of sucrose 74 times mote efficiently than sulfuric acid (39). 

Many homogeneous reactions are catalyzed by a single chemical species, usually by solvated protons or metal ions. A typical example is the hydrolysis of sucrose in aqueous solution ... 

---