the entire molecule apparatus is also named the ATP _________ complex.

1. synthetase
2. synthase
3. synthesis
4. hydrolysis

I assume the answer is either 1 or 2 because 3 and 4 are nouns and we need a verb. I lean more towards number 2. please help.

First, it is an adjective rather than a verb.

Second, you can get your answer more quickly by searching the Internet yourself. For example, I searched Google under the key words "ATP synthase complex" to get these possible sources:

(Broken Link Removed)
http://www.life.uiuc.edu/crofts/bioph354/lect10.html

I hope this helps. Thanks for asking.

Bingo!

Please see:
http://bioresearch.ac.uk/browse/mesh/D025181.html

synthetase

I apologize for the confusion in my previous response. The correct answer to the question is 1. synthetase. The entire molecule apparatus is also named the ATP synthetase complex.