I wrote the MCAT before I took either Biochem or Orgo, and I didn't take any physics courses in undergrad. I was entirely self-taught, using mainly Kaplan books and Khan Academy lectures. I scored 518 on my MCAT (129 Chem/Physics & 130 Bio). I studied for two summers while working (full-time during the first summer and part-time during the second summer). So it's definitely doable.