A new article, Drug and peptide transport in humanshttps://proteopedia.org/w/Drug_and_peptide_transport_in_humans  includes morphs illustrating the "rocker-switch" mechanism by which integral membrane transporter proteins are believed to transport nutritional peptides (from digestion of proteins) and drugs into intestinal cells. This transport is driven by the transmembrane proton gradient. Look down into the outward-facing channel while it opens and closes, intermittently revealing bound dipeptide. The sizes and shapes of the outward and inward-facing open channels are visualized by filling them with pseudoatoms (using the free program PACUPP, http://molviz.org/pacupp ). This article is based on cryo-EM structures determined by Killer et al. in the team of Christian Löw, https://www.science.org/doi/10.1126/sciadv.abk3259  -Eric Martzhttp://martz.molviz.org