Acidity and enzymes

Com symps [8029-43 ] (glucose symp, starch symp) are concentrated solutions of partially hydrolyzed starch containing dextrose, maltose, and higher molecular weight saccharides. In the United States, com symps are produced from com starch by acid and enzyme processes. Other starch sources such as wheat, rice, potato, and tapioca are used elsewhere depending on avadabiHty. Symps are generally sold in the form of viscous Hquid products and vary in physical properties, eg, viscosity, humectancy, hygroscopicity, sweetness, and fermentabiHty. 

Because of its importance to carbohydrate technology, biochemistry, and physical organic chemistry, the hydrolytic cleavage of glycosides has been extensively studied with respect to both acid and enzymic catalysis. Reviews on the acid-catalyzed hydrolysis have been presented by BeMiller, Capon, ... 

Work at the Eastern Regional Research Laboratory (35) was concerned with the de-esterification of pectin by two alternative schemes acid and enzyme. It was found that whereas enzyme de-esterification of apple pomace pectin required several minutes, acid de-esterification took 1 to 2 days. Although 40° to 50° C. was optimum for both acid and enzyme de-esterification. 

Figure 10. Comparison of acid- and enzyme-demethylated pectinates, both containing 5% of methanol...

A list of protein amino acids and enzyme systems found in coffee is given in Table 13.3... 

Protein Amino Acids and Enzymes Found in Green and Roasted Coffee3... 

Since nucleic acids and enzymes play such a large role in chromosome replication during mitosis, a considerable amount of research has been conducted in this area to control viruses. On the molecular level, analogues of nucleic acids are capable of forming complexes with adenine, cytosine, uracil, thymine, and guanine. Through complexation, these nucleic acid analogues are potential inhibitors of biosyntheses that require nucleic acids as templates. 

M Aizawa. Protein, Nucleic Acid and Enzyme. Bessatsu 31 278-280, 1987. 

A condensation reaction joins two molecules and splits out a small molecule. The small molecule is usually water. The formation of a peptide bond is an example of a condensation reaction. The conditions necessary for a condensation reaction vary with the functional groups involved. In most cases, a catalyst will be present. The two most common catalysts are acids and enzymes. Two alcohols will condense to form an ether. A carboxylic acid condenses with an alcohol to form an ester. A carboxylic acid condenses with an amine to form an amide. 

Early in the effort to develop a drug to treat HIV infection, researchers found that the virus had one potentially important "weak link in its life cycle. During the process of replication, the virus produces a very long polypeptide chain made of thousands of amino acids. This chain is similar to a protein except that it is much larger than a typical protein, so it is sometimes called a superprotein or a polyprotein. It is a polypeptide that contains within itself a number of individual proteins that the virus needs later in its replication. Some of those proteins are used to make the structural components of the cell, while others are used to make the cell s "working parts," nucleic acids and enzymes. 

Figure 5. Material and energy balance. Acid and enzyme hydrolysis following autohydrolysis and caustic extraction.

The absence of the emphasis on DNA, self-reproduction, and evolution in the theory of autopoiesis was certainly a reason for its lukewarm reception in the community of molecular biology - a difficulty that might have been avoided, had its authors been less rigid about the matter. In fact, it is not difficult to incorporate nucleic acids and enzymes into the autopoietic scheme. This was proposed more recently (Luisi, 1993 1997) and the corresponding modification is formally rather simple, as Figure 8.4 shows. 

There is another approach to the construction of the living cell, as indicated in Figure 11.1. This is to utilize the extant nucleic acids and enzymes and insert them into a vesicle, and re-construct in this way a minimal living cell. 

Srichuwong, S., Isono, N., Mishima, T., Hisamatsu, M. (2005). Structure of linterized starch is related to X-ray diffraction pattern and susceptibility to acid and enzyme hydrolysis of starch granules. Int. J. Biol Macromol, 57,115-121. 

Phosphorimetric methods have been used to determine such substances as nucleic acids, amino acids, and enzymes. However, this is not a widely used method since it cannot be run at room temperature. Measurements are usually performed with liquid nitrogen to prevent degradation due to collision deactivation. Fluorometric methods are used to determine both inorganic and organic species. Instruments used for measuring fluorescence and phosphorescence are fluorometers and spectrofluorometers, respectively. These instruments are similar to ultraviolet and visible spectrometers,... 

Maltodextrins and corn syrup solids are produced from starch, usually corn. The starch, which is almost pure carbohydrate, is cooked or pasted to open the granule and then hydrolyzed. Products can be made by hydrolyzing with acid or enzymes or with a combination of acid and enzymes. After the desired amount of hydrolysis has occurred, the reaction is stopped, and the product is filtered to remove insoluble materials and then dried. 

Gums are tasteless, odorless, colorless, and nontoxic. None, except the starches and starch derivatives, are broken down by human digestive enzymes. All are subject to microbiological attack. All can be depolymerized by acid- and enzyme-catalyzed hydrolysis of the glycosidic (acetal) linkages joining the monomeric (saccharide) units. 

Density gradients are widely used in separating and purifying biological samples. In addition to this preparative application, measurements of s can be made. Gradient techniques have been used to isolate and purify the sub-cellular components, microsomes, ribosomes, lysosomes, mitochondria, peroxisomes, chloroplasts, and others. After isolation, they have been biochemically characterized as to their protein, lipid, nucleic acid, and enzyme contents. 

Both pilot-plant and plant-scale processes for cellulose hydrolysis or digestion by acids, enzymes, and microorganisms have been built (I, 7,15,27). Acid and enzyme processes usually have as their objective the production of a sugar syrup, while the microbial process usually results in microbial protein for animal feed. Figure 10 is illustrative of a microbial process (29) that has been developed to convert the unused cellulosic material in manure to recycle feed. Similar processes have been developed... 

Hydrolysis A chemical reaction involving the reaction of a compound with water. Acid hydrolysis usually involves dilute hydrochloric acid, and enzyme hydrolysis involves enzymes such as amylase. 

Milk solids-not-fat (msnf) comprise lactose, amins, acids, and enzymes derived from milk... 

Holtmann G, Kelly DG, et al. Survival of human pancreatic enzymes during small bowel transit effect of nutrients, bile acids, and enzymes. Am/ Physiol 273 G553-G558,1997. 

Protein, Nucleic Acid And Enzyme 39(11) 181—191 Steinke W, Archimbaud Y, Becka M, Binder R, Busch U, Dupont P, Maas J (2000) Quantitative Distribution Studies in Animals Cross-Validation of Radioluminography versus Liquid-Scintillation Measurement. Regulatory Toxicology and Pharmacology 31(2) 33-43 Ullberg S (1954) Studies on the distribution and fate of S-35-labelled benzylpenicillin in the body. Acta Radiologica 1954 (suppl)l 18 1—110... 

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