Actually pre-meds now need 5 semesters of chemistry:
2 semesters gen chem w/labs
2 semesters ochem w/lab
1 semester biochem (tested on the MCAT and required by many med schools)
(And, no, you cannot simply swap ochem 2 for biochem, although some colleges/pre-health advisors may recommend this. Too many medical schools require both ochem 2 AND biochem.)
OHMomof2 is correct, you should not take any of your science requirements while abroad. You really need to do them at your home school.