Can I use parts from a MacBook in a MacBook Pro

I have a MacBook Pro A1278 that has power issues - I thought was the DC board so I replaced it, but this made no difference (but that's an issue I can't be bothered with anymore). I have been given a MacBook A1278 that had hard drive issues. I put the hard drive from the pro into the non-pro mac and no problems, all is good, everythings running as it was on the pro.

My question is: Am I able to put parts from the non-pro into the pro mac? As I'm not sure what's wrong with the pro, I was thinking (if it's possible) to use the guts of the non-pro and put it in the pro, I just don't want to pull apart the 'perfectly working' non-pro and find out things won't work.

Just in case some are wondering, why fix what aint broke? The non-pro has a 2 Ghz Processor and the pro a 2.4 Ghz, the pro has a back lit keyboard, not to mention the pro has the word pro on it (hehehe) - maybe I could just swap the keyboards and screens - least it will look like a pro hehehe