An amylase is a positive catalyst present in saliva which converts starch into maltose.
A catalyst is a substance which alters the rate of the chemical reaction without itself undergoing any chemical change. It is of two types:
(a) Positive catalyst- Catalyst which increases the rate of the reaction.
(b) Negative catalyst- Catalyst which decreases the rate of the reaction.
An amylase is a biocatalyst present in the saliva. It acts as a positive catalyst and speeds up the reaction of the conversion of starch into maltose.