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An '''amylase''' ({{IPAc-en|ˈ|æ|m|ᵻ|l|eɪ|s}}) is an [[enzyme]] that [[catalysis|catalyses]] the [[hydrolysis]] of [[starch]] (Latin ''{{Linktext|amylum}}'') into [[sugar]]s. Amylase is present in the [[saliva]] of humans and some other mammals, where it begins the chemical process of [[digestion]]. Foods that contain large amounts of starch but little sugar, such as [[rice]] and [[potatoes]], may acquire a slightly sweet taste as they are chewed because amylase degrades some of their starch into sugar. The [[pancreas]] and salivary gland make amylase ([[alpha amylase]]) to hydrolyse dietary starch into [[disaccharides]] and [[trisaccharides]] which are converted by other enzymes to [[glucose]] to supply the body with energy. Plants and some bacteria also produce amylase. Specific amylase [[protein]]s are designated by different Greek letters. All amylases are [[glycoside hydrolase]]s and act on
==Classification==
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! Optimum pH
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{{main|Alpha-amylase}}
The
Because it can act anywhere on the [[Substrate (biochemistry)|substrate]],
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In some historic methods of producing alcoholic beverages, the conversion of starch to sugar starts with the brewer chewing grain to mix it with saliva.<ref>{{cite news |title=Chew It Up, Spit It Out, Then Brew. Cheers! |url=https://www.nytimes.com/2009/09/09/dining/09beer.html?pagewanted=all&_r=0 |work=New York Times | date=8 September 2009 |access-date=27 March 2013| vauthors = Wadler J }}</ref> This practice continues to be practiced in home production of some traditional drinks, such as [[chhaang]] in the Himalayas, [[chicha]] in the Andes and [[kasiri]] in [[Brazil]] and [[Suriname]].
===Flour additive===
Amylases are used in [[breadmaking]] and to break down complex sugars, such as starch (found in [[flour]]), into simple sugars. [[Yeast]] then feeds on these simple sugars and converts it into the waste products of [[ethanol]] and [[carbon dioxide]]. This imparts flavour and causes the bread to rise. While amylases are found naturally in yeast cells, it takes time for the yeast to produce enough of these enzymes to break down significant quantities of starch in the bread. This is the reason for long fermented doughs such as [[sourdough]]. Modern breadmaking techniques have included amylases (often in the form of [[malted barley]]) into [[bread improver]], thereby making the process faster and more practical for commercial use.<ref>{{cite book |
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==Hyperamylasemia==
[[Blood serum]] amylase may be measured for purposes of [[medical diagnosis]]. A higher than normal concentration may reflect any of several medical conditions, including [[acute (medicine)|acute]] [[inflammation]] of the [[acute pancreatitis|pancreas]] (
A January 2007 study from [[Washington University in St. Louis]] suggests that saliva tests of the enzyme could be used to indicate [[sleep deficit]]s, as the enzyme increases its activity in correlation with the length of time a subject has been deprived of sleep.<ref>{{cite web|url=http://record.wustl.edu/news/page/normal/8539.html|title=First Biomarker for Human Sleepiness Identified|website=Record|publisher=[[Washington University in St. Louis]]|date=25 January 2007}}</ref>
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In 1831, [[Erhard Friedrich Leuchs]] (1800–1837) described the [[hydrolysis]] of starch by saliva, due to the presence of an enzyme in saliva, "[[ptyalin]]", an amylase.<ref>
*{{cite journal|vauthors=Leuchs EF |date=1831 |url=https://books.google.com/books?id=KSEAAAAAMAAJ&pg=PA623 |title=Wirkung des Speichels auf Stärke |trans-title=Effect of saliva on starch |journal=Poggendorff's Annalen der Physik und Chemie|volume=22|issue=8 |page=623|doi=10.1002/andp.18310980814 |bibcode=1831AnP....98..623L }} (Modern citation: ''Annalen der Physik'' '''98''' (8): 623.)
*{{cite journal|vauthors=Leuchs EF|date=1831|url=https://books.google.com/books?id=hecOAAAAYAAJ&pg=PA105|title=Über die Verzuckerung des Stärkmehls durch Speichel|trans-title=On the saccharification of powdered starch by saliva|journal=Archiv für die gesammte Naturlehre|volume=21|pages=105–107}}</ref><ref>{{cite web|url=http://www.pasteur.fr/recherche/unites/REG/causeries/dates_1800.html|title=History of Biology: Cuvier, Schwann and Schleiden|date=8 April 2002|work=pasteur.fr|access-date=17 May 2015|archive-url=https://web.archive.org/web/20150924090421/http://www.pasteur.fr/recherche/unites/REG/causeries/dates_1800.html|archive-date=24 September 2015|url-status=dead|df=dmy-all}}</ref> it was named after the Ancient Greek name for saliva: {{lang|grc|πτύαλον}} - {{lang|grc-Latn|ptyalon}}.
The modern history of enzymes began in 1833, when French chemists [[Anselme Payen]] and [[Jean-François Persoz]] isolated an amylase complex from germinating barley and named it "[[diastase]]".<ref>{{cite journal | title = Mémoire sur la diastase, les principaux produits de ses réactions et leurs applications aux arts industriels |trans-title = Memoir on diastase, the principal products of its reactions and their applications to the industrial arts | year = 1833 | journal = Annales de chimie et de physique | series = 2nd series | vauthors = Payen A, Persoz JF | volume = 53 | pages = 73–92 | url = https://books.google.com/books?id=Q9I3AAAAMAAJ&pg=PA73 }}</ref><ref>{{cite web|url=http://www.anbio.org.br/english/worksh52.htm |title=Industrial Enzymes for Food Production |archive-url=https://web.archive.org/web/20081205092157/http://www.anbio.org.br/english/worksh52.htm |archive-date=5 December 2008 }}</ref> It is from this term that all subsequent enzyme names tend to end in the suffix -ase.
In 1862,
==Evolution{{anchor|human evolution}}==
=== Salivary amylase ===
{{See also|Alpha-amylase#Salivary amylase (ptyalin)}}
[[Saccharides]] are a food source rich in energy. Large polymers such as starch are partially hydrolyzed in the mouth by the enzyme amylase before being cleaved further into sugars. Many mammals have seen great expansions in the copy number of the amylase gene. These duplications allow for the pancreatic amylase ''AMY2'' to re-target to the salivary glands, allowing animals to detect starch by taste and to digest starch more efficiently and in higher quantities. This has happened independently in mice, rats, dogs, pigs, and most importantly, humans after the agricultural revolution.<ref name=Pajic2019>{{cite journal |
Following the [[First agricultural revolution|agricultural revolution]] 12,000 years ago, human diet began to shift more to plant and animal [[domestication]] in place of [[Hunter-gatherer|hunting and gathering]]. Starch has become a staple of the human diet.
Despite the obvious benefits, early humans did not possess salivary amylase, a trend that is also seen in evolutionary relatives of the human, such as [[chimpanzee]]s and [[bonobo]]s, who possess either one or no copies of the gene responsible for producing salivary amylase.<ref>{{cite journal|
Like in other mammals, the pancreatic alpha-amylase ''AMY2'' was duplicated multiple times. One event allowed it to evolve salivary specificity, leading to the production of amylase in the saliva (named in humans as ''AMY1''). The 1p21.1 region of human chromosome 1 contains many copies of these genes, variously named ''[[AMY1A]]'', ''[[AMY1B]]'', ''[[AMY1C]]'', ''[[AMY2A]]'', ''[[AMY2B]]'', and so on.<ref name=Perry2007>{{cite journal | vauthors = Perry GH, Dominy NJ, Claw KG, Lee AS, Fiegler H, Redon R, Werner J, Villanea FA, Mountain JL, Misra R, Carter NP, Lee C, Stone AC | title = Diet and the evolution of human amylase gene copy number variation | journal = Nature Genetics | volume = 39 | issue = 10 | pages = 1256–1260 | date = October 2007 | pmid = 17828263 | pmc = 2377015 | doi = 10.1038/ng2123 }}</ref>
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This fact is especially apparent when comparing geographically close populations with different eating habits that possess a different number of copies of the ''AMY1'' gene. Such is the case for some Asian populations that have been shown to possess few ''AMY1'' copies relative to some agricultural populations in Asia. This offers strong evidence that natural selection has acted on this gene as opposed to the possibility that the gene has spread through genetic drift.<ref name=Perry2007/>
Variations of amylase copy number in dogs mirrors that of human populations, suggesting they acquired the extra copies as they followed humans around.<ref>{{cite journal |
== References ==
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