-ase

The suffix -ase is used in biochemistry to form names of enzymes. The most common way to name enzymes is to add this suffix onto the end of the substrate, e.g. an enzyme that breaks down peroxides may be called peroxidase, or an enzyme that breaks down lipids (fats) may be called lipase. Sometimes enzymes are named for the function they perform, rather than substrate, e.g. the enzyme that joins DNA strands is called polymerase (as it polymerizes DNA), and reverse transcriptase.

This suffix was likeliest extracted from the name of diastase, which was named from Greek διαστασις, "separation".

References

http://en.wikipedia.org/wiki/Amylase 
http://en.wikipedia.org/wiki/Enzyme 	
http://en.wikipedia.org/wiki/DNA_polymerase