And to demonstrate what a stem loop structure actually looks like, let's suppose it folds into the following structure. So this is the five and here and this is the three and here. Now, notice that this sequence C-U-G-A GGU, is complementary to the sequence gacucca. Now, what that means is these will essentially fold onto themselves to basically interact because these two sequences of RNA are complementary. And that means when they interact, they form these hydrogen bonds which is a stabilizing effect. And we form the following stem of this structure.