It might negatively impact your learning experience, but schools won't care at all.
This^^^^^. Labs reinforce and allow you to apply what you learn in the lecture. They are not essential, which is why they are usually offered separately, with a separate credit, but they are designed to be taken in conjunction with the lecture as a supplement to it. As long as you don't mind losing that synergy, med schools really don't care when you take it. They just want you to have some exposure to scientific lab experiences. That's why they are prereqs.
I don't know anything about a setup like that, but, clearly, a 4 credit course is meant to stand on its own. Most schools do it like my school does -- 3 credits for the lecture and 1 for the lab. You are supposed to take them together, but nothing happens if you don't.
That actually sounds like a much better setup than most schools, because most schools only give you 2 credits for the 2 labs, and they take waaay more than 1 hour per week! With your system, you get more credits to better reflect the time that actually goes into it, plus you get a lecture directed geared to the lab. The fact is, though, that your arrangement is atypical, and doesn't relate at all to OP's question, since you are forced to split the lab from the main lecture, and cannot split it from its own lecture.
