I want to know if the structure of an original journal paper (Introduction, Materials and Methods, Result and Discussion & Conclusion), is the same as a reviewed journal paper. If not, what is the structure of a reviewed journal paper?
I take your question to mean about "reviewed paper" - in which case there is no difference. In my experience, some journals have minor variations. Most essentially adhere to that set of headings.
On the other hand, did you intend to mean a "review article" which gives an overview of a topic and is based on many other sets of data?
If you mean the structure of an original research manuscript/article and that of a review manuscript, then there are differences between the structures of the two.
A review manuscript varies a lot depending on the journal requirements and/or the writer and the type of review.
Some review manuscripts follow nearly the same structure of an original research manuscript.