wait what are you talking about early decision? that doesn't exist for med school.
it depends on the school. Some schools apparently have core competencies now, so prereqs aren't technically necessary. Other med schools say it's okay to apply with 1 or 2 prereqs missing, but if it's more than that then you shouldn't bother.
Edit:MCAT and GPA also play a part. If you haven't taken the courses and then you score badly on the sections, then that looks bad. But if you score well on the MCAT for those prereqs, then you'll be good