Difference between Synthase and Synthetase

What is the difference between Synthase and Synthetase?

Synthase as a noun is any enzyme that catalyzes the synthesis of a biological compound but, unlike synthetases, does not make use of atp as a source of energy while Synthetase as a noun is any ligase that synthesizes biological compounds using atp as a source of energy

We hope you now know whether to use Synthase or Synthetase in your sentence.