Using the lock and key theory explain how the enzyme amylase is specific for breaking down starch

Amylase is an hydrolytic enzyme which is present in our saliva to digest polysaccharide such as starch.

Explanation:

Lock and Key model was proposed by Emil Fisher. According to this model a substrate binds to an enzyme same as a key binds to a lock.

In simple words it means each lock is specific for a particular key by the same way each enzyme is specific for a particular substrate,

Now comming to the matter of starch that contains glucose monomers which are linked together by alpha-1,4-glycosidic linkage.

Salivary alpha amylase cleaves the alpha 1,4 glycosidic linkage present between the glucose residues to generate alpha limit dextrin, maltose and maltitriose.

That means amylase is specific only for alpha 1,4 glycosidic linkage.