 So having started both pure beta sheet globular proteins and pure alpha helix globular proteins you can probably guess what's coming next. Mixed alpha helical and beta sheet membrane proteins. There are two types of those. First this one. Here we have a mixture where we're literally alternating alpha helices and beta sheets and the way I usually refer to that well is alpha slash beta. This structure is also helix and sheet but at least up here so here we actually have a region that's alternating but up here I have a separate beta sheet region while this is an alpha helical region so at least this part of the protein you could call alpha plus beta. Yeah sorry about the nomenclature that's not our strongest side in this field. The way I think about them and remember them is that this is alpha alternating beta while this is an alpha part plus a beta part but basically you have to learn them by heart that's what I've had to do at one point in time.