Hydrolysis of sucrose

Purpose To demonstrate the acid-catalyzed hydrolysis of a disaccharide into its component monosaccharides. 

Wear latex gloves when measuring the concenfrafedhydrochloric acid. If any acid spills on your skin, wash it off with large volumes of water and then with dilute sodium bicarbonate solution to neutralize any residual acid. 

Preparation Sign in at www.cengage.com/login to answer Pre-Lab Exercises, access videos, and read the MSDSs for the chemicals used or produced in this procedure. Review Sections 2.9, 2.11, and 2.22. 

Apparatus A 100-mL round-bottom flask, separatory funnel, 50-mL volumetric flask, polarimeter, apparatus for magnetic stirring, heating under reflux, and flameless 

Setting Up and Reaction Accurately weigh about 7.5 g of sucrose and place it in the round-bottom flask containing a stirbar. Add about 40 mL of water, swirl the contents of the flask to effect solution, and add about 0.5 mL of concentrated hydrochloric acid. Assemble the apparatus for heating under reflux. Heat the solution under reflux for about 2 h. 

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Yeast contains a number of enzymes, more particularly inyertase and zymase. Invertase catalyses the hydrolysis of sucrose to glucose and fructose (cf. the catalysis of this reaction by acids, p. 369). 

Sucrose is dextro-rotatory. Fructose shows a laevo-rotation greater in magnitude than the dextro-rotation shown by glucose. Hence as the hydrolysis of sucrose proceeds, the dextro-rotation gradually falls to zero and the solution finally shows a laevo-rotation. This hydrolysis is therefore sometimes called inversion and so the enzyme which catalyses the reaction is known as " invertase. Its more systematic name is, however, sucrase. 

Raw juice is heated, treated sequentially with lime (CaO) and carbon dioxide, and filtered. This accomplishes three objectives (/) microbial activity is terminated (2) the thin juice produced is clear and only lightly colored and (J) the juice is chemically stabilized so that subsequent processing steps of evaporation and crystalliza tion do not result in uncontrolled hydrolysis of sucrose, scaling of heating surfaces, or coprecipitation of material other than sucrose. 

Sucrose (Ci2H22On) hydrolyzes into glucose and fructose. The hydrolysis is a first-order reaction. The half-life for die hydrolysis of sucrose is 64.2 min at 25°C. How many grams of sucrose in 1.25 L of a 0.389 Af solution are hydrolyzed in 1.73 hours ... 

The hydrolysis of sucrose is a part of the digestive process. To investigate how strongly the rate depends on our body temperature, calculate the rate constant for the hydrolysis of sucrose at 35.0°C, given that k = 1.0 mL-mol -s 1 at 37.0°C (normal body temperature) and that the activation energy of the reaction is 108 kj-mol. ... 

The hydrolysis of sucrose (C12H22On) produces fructose and glucose Cl2H22On(aq) + H20(1) -> C6H,2Og(glucose, aq) + C6H 206(fructose, aq). Two mechanisms are proposed for this reaction. 

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. 

In acid, the rate of hydrolysis of sucrose is faster than the rate of degradation of its inversion products. 

INVERT (SUGAR) The product of the hydrolysis of sucrose an equal mixture of D-glucose and D-fructose. 

The hexoses that are the initial products of acid hydrolysis of sucrose (1) react at el vated temperature under the influence of acids to yield furfural derivatives (2). Thed condense, for example, with the phenols to yield triarylmethanes (3), these react furthei by oxidizing to yield colored quinoid derivatives (2, 4). Polyhydric phenols, e. g. resorj cinol, on the other hand, yield condensation products of Types 5 and 6 [2],... 

The physiologically important disaccharides are maltose, sucrose, and lactose (Table 13-4 Figure 13-11). Hydrolysis of sucrose yields a mixture of glucose and... 

Arrhenius proposed his equation in 1889 on empirical grounds, justifying it with the hydrolysis of sucrose to fructose and glucose. Note that the temperature dependence is in the exponential term and that the preexponential factor is a constant. Reaction rate theories (see Chapter 3) show that the Arrhenius equation is to a very good approximation correct however, the assumption of a prefactor that does not depend on temperature cannot strictly be maintained as transition state theory shows that it may be proportional to 7. Nevertheless, this dependence is usually much weaker than the exponential term and is therefore often neglected. 

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. 

Heterogeneous catalysts, particularly zeolites, have been found suitable for performing transformations of biomass carbohydrates for the production of fine and specialty chemicals.123 From these catalytic routes, the hydrolysis of abundant biomass saccharides, such as cellulose or sucrose, is of particular interest. The latter disaccharide constitutes one of the main renewable raw materials employed for the production of biobased products, notably food additives and pharmaceuticals.124 Hydrolysis of sucrose leads to a 1 1 mixture of glucose and fructose, termed invert sugar and, depending on the reaction conditions, the subsequent formation of 5-hydroxymethylfurfural (HMF) as a by-product resulting from dehydration of fructose. HMF is a versatile intermediate used in industry, and can be derivatized to yield a number of polymerizable furanoid monomers. In particular, HMF has been used in the manufacture of special phenolic resins.125... 

C. Buttersack and D. Laketic, Hydrolysis of sucrose by dealuminated Y-zeo-lites, /. Mol. Cat., 94 (1994) L283-L290. 

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. 

Hydrolysis of sucrose in the presence of Amberlite 200C [47-49]. Reaction conditions 9% aqueous solution of sucrose, a stirred tank [47] or continuous-flow fixed-bed reactor [48, 49]. 

The rates of a chemical reaction generally increase with temperature, an example of which is the hydrolysis of sucrose, which is 4.13 times faster at body temperature (35°C) than at room temperature (25°C). This represents a surprisingly large change in the rate of chemical reactions due to the simple rise to body temperature. It is then clear that cooling the same reactions down will slow the reactions and there is a big difference between body temperature and 10 K in an interstellar cloud. 

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) ... 

Valuable information regarding the specificity requirements of enzymes acting on carbohydrates may be expected from a discussion of fructofuranosides as substrates for enzyme action. Not only is the hydrolysis of sucrose by /3-fructofuranosidase (saccharase, invertase) one... 

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. 

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