Taking AP courses ALONG WITH getting a 4/5 in the AP exam will show colleges that you are a stronger applicant. If you're applying to high tier undergrads or Ivies, then most of the applicants you are competing with will have several APs under their belt.
If you can handle the AP courses + AP exam, then take the courses (or if you want to be competitive for higher tiered undergrads). Not only will the course give you some good background for undergrad, especially if you're planning on taking Gen Bio/Chem/Physics...etc.
*Note that some high schools won't teach the same material/won't teach it as well as others. For example, one high school may be rigorous so kids getting a B in AP bio end up with 5's in the AP exam, while another school may not teach it well, and students who get an A in the course, end up with 3's on the Exam. So do NOT use your grade in the AP course to judge your knowledge base. You MUST take the exam if you want to see how well you actually know the material. Make sure you use review books along with your class notes to supplement your knowledge to what the AP EXAM wants you to know, not what your high school teacher wants you to know.
Furthermore, without the AP exam, there's no point really to take the course besides maybe an introduction to the course material. Of course colleges will then look at your transcript and see the course but no AP Exam grade and wonder what happened to you.
But for Med School purposes, AP courses may not satisfy the course requirements as pre-requisites for applying. Like I said earlier in the thread, make sure you look at the med school's website to see what they say about AP courses as pre-requisites. I know that for many schools, if you place out of Gen Bio pre-requisite with AP bio, they will want to see harder 300-400 biology courses to supplement your Bio pre-requisite.
Finally, Med Schools don't really care about what undergrad you go to, so you can go to any undergrad whether it's an Ivy or a lower tier. As long as you have a good GPA and a good MCAT score supplemented by your ECs.
However, I will say this, going to a higher tier undergrad myself, compared to some of my friends who went to other schools, I found myself working less when preparing for the MCAT to achieve a good score, because the higher tier undergrad really taught me the material in depth and helped me retain it. Especially for you guys taking the 2015 MCAT with Biochemistry.