When a reaction is catalyzed:

a) Is the catalyst involved in the reaction? (State your evidence)

b) Has the catalyst been consumed when the reaction is complete?

2 answers

a) Yes, you can probably tell because the activation energy gets lower and thus allow the reaction to speed up way faster than without a catalyst... it's kind of dumb to ask if in catalyst is involved in a CATALYZED reaction...

b) No, the catalyst will get recycled at the end of the reaction.
a)Yes, the catalyst enters into the reaction.
b) Although the catalyst enters into the reaction, it is regenerated in a subsequent step; the net effect is that none of it is consumed.
Here is a site that gives some examples.
http://en.wikipedia.org/wiki/Catalyst