From what I understand the science GPA carries much more weight. However, the cumulative GPA still is looked at. That being said, most people's science GPA tend to be lower than their cumulative GPA. I would say that a 3.5 science GPA is normal for someone with a 3.6 cumulative GPA.
Averages for those accepted to MD schools are cGPA 3.67 and BCPM 3.61. Those are good goals to hit, but grade trend is important too. So if you show an upward grade trend, a lower BCPM is OK. With a more than modest downward trend, it would be a good idea to delay application until that is corrected.