I understand that when naive B cells are exposed to antigens, they become memory B cells, but what is the functional difference between the two? I've looked at the quite a few article on B cells, but none of them stated the difference clearly enough for me to understand.
The main difference is that memory B cells start an immune reaction much more effective and faster than naive B cells. The reaction is also specific towards the antigen.
The memory B cell has a specific membrane receptor for an antigen. It produces specific antibodies only when exposed to the antigen.
Naive B cells have not yet been trained by the immune system to recognize specific antigens -therefore the term "naive". Prior to antigen exposure, they must be trained in the bone marrow to recognize certain antigens.
Memory B cells, on the other hand, are formed after antigen exposure and clonal selection. As stated above, they have specific receptors for antigens and can produce antibodies.