Editing Amylase (section)

==Classification==

{| class="wikitable"
|-
! 
! α-amylase
! β-amylase
! γ-amylase
|-
! Source
| Animals, plants, microbes
| Plants, microbes
| Animals, microbes
|-
! Tissue
| Salivary gland, pancreas
| Seeds, fruits
| Small intestine
|-
! Cleavage site
| Random α-1,4 glycosidic bond
| Second α-1,4 glycosidic bond
| Last α-1,4 glycosidic bond
|-
! Reaction products
| [[Maltose]], [[dextrin]], etc.
| Maltose
| [[Glucose]]
|-
! Optimum pH
| 6.7–7.0
| 5.4–5.5
| 4.0–4.5
|-
! Optimum temperature in brewing
| {{convert|68|–|74|C|F}}
| {{convert|58|–|65|C|F}}
| {{convert|63|–|68|C|F}}
|}

===α-Amylase===
{{main|Alpha-amylase}}
The α-amylases ({{EC number|3.2.1.1 }}) ([[CAS registry number|CAS]] 9014–71–5) (alternative names: 1,4-α-<small>D</small>-glucan glucanohydrolase; glycogenase) are [[calcium]] [[metalloprotein|metalloenzymes]]. By acting at random locations along the starch chain, α-amylase breaks down long-chain [[saccharides]], ultimately yielding either [[maltotriose]] and [[maltose]] from [[amylose]], or maltose, [[glucose]] and [[dextrin|"limit dextrin"]] from [[amylopectin]]. They belong to [[glycoside hydrolase family 13]] (https://www.cazypedia.org/index.php/Glycoside_Hydrolase_Family_13).

Because it can act anywhere on the [[Substrate (biochemistry)|substrate]], α-amylase tends to be faster-acting than β-amylase. In [[animal]]s, it is a major [[digestion|digestive]] enzyme, and its optimum pH is 6.7–7.0.<ref>{{cite web|url=http://www.worthington-biochem.com/introbiochem/effectspH.html|title=Effects of pH (Introduction to Enzymes)|website=worthington-biochem.com|access-date=17 May 2015}}</ref>

In human physiology, both the salivary and pancreatic amylases are α-amylases.

The α-amylase form is also found in plants, fungi ([[ascomycetes]] and [[basidiomycetes]]) and bacteria (''[[Bacillus]]'').

===β-Amylase===
{{main|Beta-Amylase}}
Another form of amylase, β-amylase ({{EC number|3.2.1.2 }}) (alternative names: 1,4-α-<small>D</small>-glucan maltohydrolase; glycogenase; saccharogen amylase) is also synthesized by [[bacteria]], [[fungi]], and [[plant]]s. Working from the non-reducing end, β-amylase catalyzes the hydrolysis of the second α-1,4 glycosidic bond, cleaving off two glucose units ([[maltose]]) at a time. During the [[ripening]] of [[fruit]], β-amylase breaks starch into maltose, resulting in the sweet flavor of ripe fruit. They belong to [[glycoside hydrolase family 14]].

Both α-amylase and β-amylase are present in seeds; β-amylase is present in an inactive form prior to [[germination]], whereas α-amylase and proteases appear once germination has begun. Many [[microbe]]s also produce amylase to degrade extracellular starches.  [[Animal]] tissues do not contain β-amylase, although it may be present in microorganisms contained within the [[Gastrointestinal tract|digestive tract]]. The optimum pH for β-amylase is 4.0–5.0.<ref name="worthington-biochem.com">{{cite web|url=http://www.worthington-biochem.com/BA/default.html |title=Amylase, Alpha, I.U.B.: 3.2.1.11,4-α-D-Glucan glucanohydrolase}}</ref>

===γ-Amylase{{anchor|Flatulence}}===
<!-- This section is linked from [[Flatulence]] -->
{{main|Glucan 1,4-a-glucosidase}}
γ-Amylase ({{EC number|3.2.1.3 }}) (alternative names: Glucan 1,4-a-glucosidase; amyloglucosidase; ''exo''-1,4-α-glucosidase; glucoamylase; lysosomal α-glucosidase; 1,4-α-<small>D</small>-glucan glucohydrolase) will cleave α(1–6) glycosidic linkages, as well as the last α-1,4 glycosidic bond at the nonreducing end of [[amylose]] and [[amylopectin]], yielding [[glucose]]. The γ-amylase has the most acidic optimum pH of all amylases because it is most active around pH 3. They belong to a variety of different [[glycoside hydrolase]] families, such as [[glycoside hydrolase family 15]] in fungi, [[glycoside hydrolase family 31]] of human [[Maltase-glucoamylase|MGAM]], and [[glycoside hydrolase family 97]] of bacterial forms.