Enzyme amylases

Starch A polymeric substance of glucose molecules and a component of many terrestrial and aquatic plants used by some organisms as a means of energy storage starch is broken down by enzymes (amylases) to yield glucose, which can be used as a feedstock for chemical or energy production. 

Unlike many of the catalysts that chemists use in the laboratory, enzymes are usually specific in their action. Often, in tact, an enzyme will catalyze only a single reaction of a single compound, called the enzyme s substrate. For example, the enzyme amylase, found in the human digestive tract, catalyzes only the hydrolysis of starch to yield glucose cellulose and other polysaccharides are untouched by amylase. 

When you eat starchy foods, they are broken down into glucose by enzymes. The process starts in your mouth with the enzyme amylase found in saliva. This explains why, if you chew a piece of bread long enough, it starts to taste sweet The breakdown of starch molecules continues in other parts of the digestive system. Within 1 to 4 hours after eating, all the starch in food is converted into glucose. 

Hydrolases such as the digestive enzymes amylase and lactase catalyse hydrolysis of glycosides, esters, anhydrides and amides. 

Diabetic patients have reduced antioxidant defences and suffer from an increased risk of free radical-mediated diseases such as coronary heart disease. EC has a pronounced insulin-like effect on erythrocyte membrane-bound acetylcholinesterase in type II diabetic patients (Rizvi and Zaid, 2001). Tea polyphenols were shown to possess anti-diabetic activity and to be effective both in the prevention and treatment of diabetes (Choi et al, 1998 Yang et al, 1999). The main mechanism by which tea polyphenols appear to lower serum glucose levels is via the inhibition of the activity of the starch digesting enzyme, amylase. Tea inhibits both salivary and intestinal amylase, so that starch is broken down more slowly and the rise in serum glucose is thus reduced. In addition, tea may affect the intestinal absorption of glucose. 

Enzymes Amylase, invertase, cellobiase, desoxyribonuclease, ribonu-clease, acid phosphatase, phyta.se, pyrophosphatase apy-rase, peroxidase, protease... 

Pancreatic enzyme supplements should be taken immediately prior to meals to aid in the digestion and absorption of food. Alternately, patients can supplement their diet with medium chain triglycerides (MCTs) or ingest foods rich in MCTs since they do not require pancreatic enzymes for absorption. An appropriate regimen incorporates the successful doses of each enzyme (amylase, lipase, and protease) from the starting non-enteric-coated regimen. As with the previous example, a patient stabilized on Viokase-8, six tablets with each meal, can be transitioned to Pancrease MT-16 three tablets with meals. The famotidine can then be discontinued. 

Homogenization in NaOAc buffer and Na cyanide addition of enzyme amylase and pepsin (for total vitamin) incubation at 32°C for 30 min (or 37°C for 3h) immuno-affinity column... 

As has been described in a recent review of low-molecul2u -welght enzyme inhibitors of microbial origin (65), hypotensive coo unds, ccmipounds useful in the treatment of diabetes or obesity, and con unds useful in the treatment of hypercholestremla have been discovered by the screening for inhibitors of catecholamine-synthesizing enzymes, amylase, or 3-hydroxy-3 metl lglu-taryl coenzyme A reductase respectively. 

Starch derived from maize, potatoes, barley, cassava or other somces must be pretreated with hydrolytic enzymes (amylases, amyloglucosidase, proteases), which carry out liquefaction, saccharification and protein hydrolysis, respectively, before it can be fermented by yeasts and other microorganisms into potable or non-potable alcohol. Enzymes can be added in the form of malt (germinated barley) or koji (germinated rice), but this is expensive. Therefore, industrial enzymes have nearly totally replaced malt and koji as enzyme sources, thereby not only improving the economics but also the predictability of the process. 

D-glucose. This reaction demonstrates the basic difference between the structure of starch and that of cellulose. Starch, in contact with an enzyme amylase (diastase), is broken down to form a different biose maltose, which when hydrolysed in the presence of acid is also converted into D-glucose. 

Once in the active site, the substrate undergoes reaction. The product is then released for use in the next stage, which is controlled by another enzyme, and the original enzyme molecule is free to receive the next substrate molecule. One example is the enzyme amylase present in your mouth. The amylase in saliva helps to break down starches in food into the more easily digested glucose. If you chew a cracker long enough, you can notice the increased sweetness. 

Albumins and globulins 12-20 Extractable by water of dilute salt solutions (e.g., 0.1-0.5 M NaCl) Contains enzymes (amylases, proteinases, lipoxygenases) Rich in Lys, Asp, Ala, Cys, Leu, and Arg low in Met content... 

The enzyme amylase is present in the small intestines, too, so the digestion of carbohydrates can continue there. The carbohydrates eventually are broken down into their simplest form— glucose—which cells can use during respiration to produce the energy the body needs to function. 

In addition, they increase the size of many young fruits, expe-cially grapes. Because gibberellins induce the production of the enzyme amylase in barley, they also are commonly used in the malting of barley. 

The breakdown of food begins in the mouth as it is chewed. Chewing mixes saliva in the food. Saliva contains the enzyme amylase that begins the digestion of starch. Once chewed and swallowed, the food reaches the stomach, where the acid present... 

In pine, it was found that Bacillus polymyxa was the major species involved (45, 55), whereas, in spruce the major species were Bacillus subtilis and Flavobacterium pectinovorum (49). In another study (53), Clostridium omelianskii was identified as the species attacking softwoods. In all studies, it was found that the bacterial attack on the pit membranes was the reason for increased permeability of the wood. Furthermore, it was shown by Fogarty and Ward (49) that bacteria degraded the pit membranes by excreting the enzymes amylase xylanase, and pectinase. A typical sapwood pit membrane that has been attacked by bacteria is shown in Figure 2. As can be seen, the torus is severely degraded and has well defined openings. 

A number of relatively new methods are being investigated to improve the recovery of small molecules. These methods include elec-trokinetic separators with bipolar membranes, simulated moving-bed chromatography and supercritical fluid extraction. The latter is practiced for food components. It has also been described for proteins but has not yet found wide acceptance in this field. A fastgrowing field is the production of bioethanol via fermentation processes either from milled com or from recycled biomass. The fermentation and saccharification processes can occur simultaneously in the fermenting tank by means of saccharification enzymes (amylases, cellulases). 

Enzymes Amylase, cellulase, protease, lipase, lab Food processing, tanning, detergents additives... 

Pancreatic juice contains an alkaline fluid and enzymes, both of which empty into the duodenum. The alkaline pH contributes to neutralization of the acid that empties from the stomach. The enzymes amylase, lipase, trypsin, and chymotrypsin play major roles in the digestion of carbohydrates, fats, and proteins. Trypsin and chymotrypsin are secreted as inactive precursors and are converted to the active forms enzymatically. 

Glycogens are attacked by three known groups of enzymes amylases and phosphorylases degrade a-D-(l 4)-linkages, whilst a-D-(l 6) inter-chain linkages are hydrolyzed by debranching enzymes. -... 

Microbial fermentation of CSM, which was proposed to detoxify FG in the CSM (Zhang et ah, 2006a,b), seems promising because some exoenzymes such as cellulolytic enzymes, amylase, protease, and lipolytic enzymes that are secreted by certain microorganisms, and some vitamins, as well as some unknown active substances are produced in the fermented CSM (Brock et ah, 1994), which adds nutritional value of the fermented CSM. Recently, Qian et ah (2008) reported that in situ alkaline-catalyzed transesterification could produce a CSM with FG and TG contents below the FAO standard. However, the requirement for a high amount of methanol usage in the in situ transesterification and the potential energy consumption to remove the methanol in the meal may be an obstacle for its practical application. 

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