On the computational power of flip-flop proteins on membranes

P Systems with proteins on membranes were introduced recently by A.Paun and B. Popa, in an effort to bridge the gap between membrane computing and brane calculi. In this variant, one considers multisets of objects inside the membranes as well as proteins on the membranes. The action of the proteins on the objects is classified broadly into 5 categories. In this paper, we study the computational power of these actions and come up with upper and lower bounds in terms of computational power for some of them.