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See Article History Alternative Titles: Two categories of amylases, denoted alpha and beta, differ in the way they attack the bonds of the starch molecules.
Alpha-amylase is widespread among living organisms. In the digestive systems of humans and many other mammals, an alpha-amylase called ptyalin is produced by the salivary glandswhereas pancreatic amylase is secreted by the pancreas into the small intestine.
Ptyalin is mixed with food in the mouth, where it acts upon starches. Although the food remains in the mouth for only a short time, the action of ptyalin continues for up to several hours in the stomach—until the food is mixed with the stomach secretions, the high acidity of which inactivates ptyalin.
Under optimal conditions as much as 30 to 40 percent of ingested starches can be broken down to maltose by ptyalin during digestion in the stomach. When food passes to the small intestinethe remainder of the starch molecules are catalyzed mainly to maltose by pancreatic amylase.
This step in starch digestion occurs in the first section of the small intestine the duodenumthe region into which the pancreatic juices empty.
The by-products of amylase hydrolysis are ultimately broken down by other enzymes into molecules of glucose, which are rapidly absorbed through the intestinal wall.
Beta-amylases are present in yeasts, molds, bacteriaand plants, particularly in the seeds. They are the principal components of a mixture called diastase that is used in the removal of starchy sizing agents from textiles and in the conversion of cereal grains to fermentable sugars.
Learn More in these related Britannica articles:Amylase: Amylase, any member of a class of enzymes that catalyze the hydrolysis (splitting of a compound by addition of a water molecule) of starch into smaller carbohydrate molecules such as maltose.
Two categories of amylases, denoted alpha and beta, differ in the way they attack the bonds of the starch molecules. Variations in soil physicochemical properties and enzyme activities under different land use types are shown in Table 1.
SWC of rapeseed, broad bean and wheat fields were %, % and %, respectively, significantly lower than that of aquaculture ponds (%). Brazilian Archives of Biology an analysis of the properties of the enzyme amylase and Technology On-line version ISSN Braz.
Submissions from 3 Curitiba May/June The Federal University of Technology, Akure (FUTA) is a top ranking University of technology in Nigeria and indeed the nation's pride.
Established in. Feb 11, · Genomic analysis of the hyperthermophilic archaeon Pyrococcus furiosus revealed the presence of an open reading frame (ORF PF) similar to the enzymes in glycoside hydrolase family This amylolytic enzyme, designated PFTA (Pyrococcus furiosus thermostable amylase), was cloned and expressed in Escherichia coli.
Alpha-amylase, is a protein enzyme EC that hydrolyses alpha bonds of large, alpha-linked polysaccharides, such as starch and glycogen, yielding glucose and maltose.
It is the major form of amylase found in humans and other mammals. It is also present in seeds containing starch as a food reserve, and is secreted by many fungi. Mar 16, · A novel liquefying α-amylase (LAMY) was found in cultures of an alkaliphilic Bacillus isolate, KSM The specific activity of purified LAMY was approximately 5, U mg of protein −1, a value two- to fivefold greater between pH 5 and 10 than that of an industrial, thermostable Bacillus licheniformis enzyme.
The enzyme had a pH optimum of to and displayed maximum activity at .