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 **Amylase**

__**Overview**__
Amylase is an enzyme that hydrolyzes starch into smaller carbohydrate fragments. Starch is a macromolecule polymer consisting of glucose monomer units. Starch is stored in plants as a form of a carbohydrate reserve, and in animals they are stored as glycogen. Amylase digests starch into reducing fermentable sugars mainly as maltose, which can undergo further hydrolysis reactions into fermentable dextrins under anaerobic conditions, or in the presence of oxygen, are further broken down into glucose (McGraw-Hill Science & Technology Encyclopedia).

Amylase is mainly found in the saliva and in the pancreatic juice. The amylase found in saliva is ptyalin, and the amylase found in the small intestine is amylopsin, which is secreted by the pancreas[5].

__**Classes of Amylase**__
// Before coming to specific information about different kinds of amylase, let's watch a short video first!!! //

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//**Generally, amylase is an enzyme that function in breaking down starch and converting it into sugar.**//

The three classes of Amylase are α-amylase, β-amylase, and γ-amylase.
**α-Amylase** in human catalyzes the hydrolysis of α-1,4 glucan linkages in starch. It can be found in the saliva and pancreas (α-Amylase from those have the same primary sequences and similar function). The ptyalin known as salivary amylase digests a linear α (1,4) glycosidic linkage by breaking down a large, insoluble starch molecule into soluble starches such as amylodextrin, erythrodextrin, achrodextrin [12]. Furthermore, pancreatic α-amylase breaks down the α (1-4) glycosidic linkages of amylose in order to yield glucose, maltose, dextrin, and maltotriose[8] However, α-Amylase is not only found in human but also other organisms because starch is one of the most important source of energy for all living things. Therefore, α-Amylase plays an important role in maintaining the existence of plants, humans, mammalian tissues and microorganisms [13]. Other important information is α-Amylase can only function in the presence of calcium[6]. In generally, alpha amylase is more active than beta amylase due to the fact they can act everywhere on the substrate. Moreover, Both enzymes found in saliva and pancreases function as digestive enzymes. Salivary enzyme has optimal pH from 5.6 to 6.9, while pancreatic enzyme has optimal pH from 6.7 to 7.0 [14] Especially, an inhibitor of alpha amylase called phaseolamin can be found in plants such as bean Phaseolus vulgaris. An alpha Amylase inhibitor has 3 different isoforms includingalphaAI-1, alphaAI-2 and alphaAI-3. Alpha Al-1, the most common alpha amylase inhibitor was purified and analyzed in the middle of year 1970. AlphaAI-1 inhibits alpha-amylase in animals and establishes the basis of a dietary supplement introduced into the dietary supplement marketplace in the early 1980s [15]. AlphaAl-1 plays the role as "starch blocker" because it can lower plasma glucose levels and contribute to reduction in weight. The problem was it didn't seem to work on human and mostly disappeared from the drug market. However, in the beginning of 2000, phaseolamin became more popular and increased the interest in low-carbohydrate diets for weight management.

** Salivary alpha-amylase in human **

**Crystal structure of human pancreatic α-amylase**



**β-Amylase** is found in plants and bacteria, not in human [16]. It is responsible for the sweet taste of ripe fruit[7]. β-Amylase yields maltose. An beta amylase seems to be really picky because it digests only from one end of the starch molecule. Besides that, it tends to digest on the "reducing" end of a starch molecule with two glucose units bitten at the same time [18] In 1940, beta amylase was first purified. Then 1948, Hopkins began to do research about kinetics of beta amylase [19] In 1960 and 1970, beta amylase in sweet potatoes was improved by using techniques in its purification [19] β-amylase was successfully cloned and expressed in E. coli in 1991[19] Until 2001, the simple purification method which is used affinity precipitation was approved [19] **// Enzymatic Reaction: //** Beta-Amylase is an extracellular enzyme that releases maltose through hydrolysis of a polysaccharide chain. It is found primarily in the seeds of plants that have high elevation, and its only product is maltose. [10] ** //Application:// ** Beta-Amylase is mainly used in the study of starch and glycogen structure, hydrolysis of starch, and fermentation in brewing/distilling. [10] **// Composition: //** Beta-Amylase is composed of a single polypeptide chain //**Optimal pH:**// The optimal pH of Beta-Amylase is about 5. [11] **Beta-amylase** // Let's watch to understand how Beta Amylase is isolated from sweet potato // ** Isolation of Beta Amylase from Sweet Potato ** media type="youtube" key="MY7Vi6nSYBQ" width="339" height="280" align="center"
 * History of Beta Amylase: **

**γ-Amylase** is found in fungi dividing one β-D-Glucose molecule from the molecular chain end. γ-Amylase cleaves the last alpha-1,4-glycosidic linkages and the alpha-1-6-glycosidic linkages to yield glucose [9]. Especially, it is the most efficient in acidic environment and has optimal pH of 3.0 [17]

** Amylase Gamma (Amyg) **

__**History**__ In 1831 Erhard Friedrich Leuchs first discovered amylase through the hydrolysis of starch by means of salivary enzymes called “ptyalin.”[4] The progression of Amylase continued in 1833 through the work of Anselme Payen a director a t a sugar factory[2]. Payen precipitated ethanol and an isolated powder from germinating barley, therefore creating a substance capable of hydrolyzing starch[2]. Later in 1836 Theodor Schwann discovered an amylase enzyme found in gastric juice of an animal. He precipitated the liquid and isolated the enzyme[1], naming it pepsin. A break through in 1874 made by Christian Hansen, the Danish chemist extracted a complex of enzymes in a calf stomach with a saline solution. This was the first pure form of amylase for industrial purposes. After these discoveries the evolution and development of Amylase continued for several years through the works of many like Theodor Schwann, Justus Von Liebig, Louie Pasteur, and Wilhelm Kuhne.

__**Use of Amylase**__ The use of Amylase varies in different and significant fields [16]:
 * 1) Production of alpha amylase goes along the help of genetically modified types of bacillus. Furthermore, amylase is produced through aspergillus-fungi cultures
 * 2) Especially, amylase is used wildly in food industry. For example, amylase is one of specially tools that is used in bread making by its help to improve gas information.
 * 3) Besides that, amylase is used to break down cheaply made maize or potato starch into maltose and glucose molasses which play an important role in the food industry
 * 4) Amylase has a major contribution to the fermentation of alcohol
 * 5) Amylase is also used in clothing detergents to dissolve starches
 * 6) Furthermore, bacterial amylase can have a strong impact to gene technology because their amylase is more stable and strongly exist in hash condition of temperature. Bacterial amylase now can be produced with genetically modified microorganisms. Moreover, in the way of using fungi to produce amylase, used cultures are not regarded as genetically modified

__**Works Cited**__

1]Danchin, Antoine. "History of Biology 1800-1849." //Normalesup.org//. Web. 07 Dec. 2011. . [2]Hill, Robert, and Joseph Needham. //The Chemistry of Life; Eight Lectures on the History of Biochemistry,//. Cambridge [Eng.: University, 1970. Print. [3]"History of Enzymes, Industrial Enzyme History, Textile Enzyme, Leather Bating, Detergent Enzymes." //Enzymes, Biotechnology, Industrial Enzymes, Textile Enzymes, Leather Enzymes//. Maps Enzymes Limited. Web. 07 Dec. 2011. . [4]"History of Medicine." //Target Health Global//. Target Health Global. Web. 07 Dec. 2011. . [5]"Amylase information page." //Zest For Life//. Sallamander Concepts, n. d. Web. 8 Dec. 2011. .

[6] Minich, Deanna. //An A-Z Guide to Food Additives: Never Eat What you Can't Pronounce//. San Francisco: Conari Press, 2009. 11. eBook. [7] "Beta-Amylase." 8/10/2009. n.pag. //Biology Online//. Web. 10 Dec 2011. .

[8] "Amylase." //enzyme-facts.com//. 2009. Web. 10 Dec 2011. <http://www.enzyme-facts.com/amylase.html>.

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 110%;">[9] "Amylase." //Great Vista Chemicals//. n. page. Web. 10 Dec. 2011. <http://www.greatvistachemicals.com/biochemicals/amylase.html>.

[10] Worthington, Krystal. "Amylase, Beta - Worthington Enzyme Manual." Enzymes, Biochemicals: Worthington Biochemical Corporation. Worthington Biochemical Corporation. Web. 12 Dec. 2011. <http://www.worthington-biochem.com/ba/default.html>.

[11] Eyster, Clyde. "The Optimum PH for Diastase of Malt Activity." The Ohio Journal of Science 5th ser. 59 (1959). The Ohio Journal of Science. Web. 13 Dec. 2011. <https://kb.osu.edu/dspace/bitstream/handle/1811/4633/V59N05_257.pdf?sequence=1>.

[12] "Alpha amylase ". Biology Online. Web. 11 Dec 2011. Retrieved from http://www.biology-online.org/dictionary/Alpha-amylase

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 110%; line-height: 21px;">[13] "Alpha amylase orthologs" Davidson College. Web 13 Dec 2011. Retrieved from http://www.bio.davidson.edu/Courses/Molbio/MolStudents/spring2010/Webb/orthologs.html

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 110%;">[14] "Effect of pH- Introduction of enzymes" Worthington. Web 13 Dec 2011. Retrieved from http://www.worthington-biochem.com/introbiochem/effectspH.html

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 110%;">[15] "Alpha amylase inhibitor (Phaseolamin)". Pure matters. Web. 11 Dec 2011. Retrieved from http://www.purematters.com/herbs-supplements/a/alpha-amylase-inhibitor-phaseolamin

[16] "Use of amylase". Web. 13 Dec, 2011. Retrieved from http://www.ursprung.at/ursprung/projekte_extern/amylase/en/amylase.php?seite=amylase1

[17] "Amylase Gamma (Amyg)". Web. Dec 13, 2011. Retrieved from http://www.uscnk.us/item/90793.html

[18] "Fun with amylase". Science project.com. Web. Dec 13, 2011. Retrieved from http://www.science-projects.com/Amylase.htm

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 110%;">[19] "Amylase, Beta". //History.//Worthington. Web 13 Dec 2011. Retrieved from http://www.worthington-biochem.com/introbiochem/effectspH.html