The entire ATP apparatus is also called the ATP_______

I think it is Synthesis but not sure.

ATP synthesis is a process.
apparatus is a noun.
you need a noun.

ATP----------------?

I can't seem to think of an appropriate word. Sometimes I seriously wopnder about the teachers that make up these questions.

Is it then Synthase?

atp synthase is a noun, but only refers to a specific enzyme in the process.

The entire ATP apparatus is also called the ATP synthase.

ATP synthase is a protein complex located in the inner membrane of mitochondria in eukaryotic cells and in the plasma membrane of prokaryotic cells. It is responsible for the synthesis of adenosine triphosphate (ATP) through a process called oxidative phosphorylation.