Question

Which of the following is true of an enzyme? Choose all that apply.
It is a protein.
It is a catalyst.
It binds to many different substrates.
It is small compared to its substrates.

Answer 1

It is a protein, catalyst.

Answer 2

protein and catalyst.

Answer 3

enzyme could be RNA

Answer 4

http://en.wikipedia.org/wiki/Ribozyme

Answer 5

It is a catalyst. :)

Answer 6

I guess that you are correct and enzymes can really only be reduced to their catalytic activity. however, if you are still in school, you may want to also check 'protein'. I don't know a school where the RNA world would be much of a concern, to be honest. so if I was the asker, I would take abhisars answer.

note also that for every criteria that is listed, you can find an enzyme that it fits. DNA binding proteins fit no. 4, while proteases fit no. 3. but that's off-topic.