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2.  Amylase are starch degrading enzymes.
 First discovered enzyme was named as
<diastase> in 1833.
 It belongs to the glucoside hydrolase group of
enzymes under which 13 enzymes are
included.
 These enzymes act by hydrolyzing glycosidic
bonds-σ-1,4 glycosidic bonds and σ-1,6
glycosidic bonds between adjacent glucose
units.

3.  Starch is a polymer of glucose linked to
another one through the glycoside bond.
 2 types of glucose polymers are present in
starch: amylose and amylopectin.
 amylose:linear polymer consisting of upto
6000 glucose units with σ-1,4glucosidic
bonds.
 amylopectin:consists of short σ-1,6 linked
to side chains with 15-45 glucose units.
 Amylase is able to cleave this glycosidic
bonds present in inner part of the amylose or
amylopectin chain.

4.  Enzymes that hydrolyze σ-1,4 bonds e.g.
σ-amylase(endoacting amylases).
 Enzymes that hydrolyze σ-1,4 e.g.β amylase
(exoacting amylases).
 Enzymes that hydrolyze terminal 1,4 linked
σ D-glucose residues.e.g.glucoamylase.
 Enzymes that hydrolyze only σ-1,6 linkages
e.g. pullulanase.
 Enzymes that hydrolyze preferentially σ-1,4
linkages in short chain oligosaccharides
produced by the action of other enzymes on
amylose and amylopectin e.g.σ glucosidases.

5.  The human σ-amylase is a classical calcium
containing enzyme composed of 512 amino
acids with molecular weight of 57.6kDa.
 The A domain is the largest,presenting a
typical ‘tim barrel’ shaped super structure.
 The B domain is the smallest domain
attached to the A domain by disulphide bond.
 The C domain is made up of anti-parallel
beta-structure and is loosely associated with
domains A and B.

7.  The Enzyme-substrate reaction can be
determined by measuring the increase in
reducing sugars using the 3,5 dinitro salicylic
reagent.
 The reagent undergo reduction in presence
of reducing sugar to yield orange colored 3-
amino-5-nitrosalicylic acid.
 The absorbance of resultant solution is read
at 540nm.

8.  Starch conversion
 Bakery
 Detergent industry
 Textile industry
 Fuel production
 Paper industry
 Pancreatic enzyme replacement therapy