What are the minimal admissions requirements?
Generally, most medical schools require one year each of general biology, general chemistry, organic chemistry and physics designed for science majors. All courses should have laboratory components. At the University of Cincinnati, that translates to BIOL 101-103 (lecture) and 111-113 (lab), CHEM 101-103 and 111-113, CHEM 201-203 and 211-213 and PHYS 101-103 and 111-113. Many schools also require one year of college-level math. Speak to a pre-professional advisor about your math options.
Some schools also require or recommend upper level sciences, a year of English composition, humanities and/or social sciences. You should consult the admissions literature for the specific requirements and recommended courses at each school in which you are interested. If you are interested in a particular school, you should learn as much about that school as you possibly can early on.