(enzyme) Any enzyme that catalyzes the synthesis of a biological compound but, unlike synthetases, does not make use of ATP as a source of energy
(enzyme) Any ligase that synthesizes biological compounds using ATP as a source of energy.
an enzyme which catalyses the linking together of two molecules, especially without the direct involvement of ATP
‘nitric oxide synthases’;
In biochemistry, a synthase is an enzyme that catalyses a synthesis process. Note that, originally, biochemical nomenclature distinguished synthetases and synthases.