I just this week visited the university I am considering applying to in a few years and spoke with one of the faculty in the anesthesia program regarding my weak chemistry background. First of all, it was HUGELY informative speaking with this professor, and I highly recommend it for anyone who has questions about a CRNA program or needs some individualized counseling regarding the best classes to take to get in a good position for applying in a year or two. I basically have almost no chemistry to speak of and did poorly in my sciences way back in my bachelor's degree many moons ago. When I went to nursing school, I went for an ADN and did not have to take any chemistry at all. I was told by this professor that I need to take a basic chemistry course (he said it doesn't really matter where I take it, as long as the school is accredited) and ace it, considering my poor record during my bachelor's.
Then I will need to take an organic chemistry, and this university happens to offer a really tough one online. If I manage to wrap my head around general chemistry (I'm determined!), then I will take that online course. If I do well on both of those and the GRE (did really well on the SAT eons ago, so hopefully that is an indication), my app will look pretty good. I did ask him about physics and statistics and biochem (all of which I am also totally ignorant of), and he stated they would be very helpful for me as far as making the CRNA program more doable, but that they would not be required.
So that's where I stand.......I'm already on a list to get the schedule for the chemistry course starting this January at my local community college, and we'll go from there. I think chemistry is so basic to everything you do in CRNA school that I am determined to get a good foundation in it.
Again, I'd highly recommend talking to somebody at a CRNA program you would be interested in attending so that you are not stabbing about in the dark as to what classes you should take or what preparations you should make.