I finding yelling "lelelelelele" gears me up for anything.
Besides that, I think it's impossible to always feel motivated, so the trick is to perform even when you don't feel up to it. I won't get all high and mighty, I think it happens to the best of us.
In your case try:
- splitting up the work days a bit more.
- remember that while the courses are way easier than your BCPM, they show how well you can jump through hoops, this is important.
- finishing the stuff you don't care about first, or starting the assignments very early so you can tend to them as the motivation comes along.
- remember that while your science GPA is crucial, "easy classes" hurt your overall GPA, so you don't want to be in the "damn I should of just tried harder on that stupid class" situation.
Even though I was accepted, applications wouldn't been been so terrifying if I had tried on my fluff courses, or at least bought the book =).