You sound just like me. I can't memorize anything to save my life, am very conceptual so I had a great time with orgo and a terrible time with bio.(And can't study at night!) For the MCAT I started out getting 8,9, 10 on bio section on practice tests, and started attacking memorizing bio through learning the concepts, visualizing the systems, drawing them out, trying to figure out where everything ended up in the "bigger picture." For things I HAVE to memorize, I cuse acronyms oer little word tricks to help me remember. I ended up getting a 13 on the bio section by understanding concepts rather than memorizing. You'll be fine!