Protein interactions, cell membrane. Clip 5 of 7. Animation showing proteins interacting on a cell membrane, some embedded and some free_floating. Some membrane proteins receptors bind to and detect free_floating proteins. Others form structures called ion channels, mediating the flow of ions in and out of the cell. Towards the end of this clip, several potassium ion channels are seen releasing ions spheres. This clip is part of a sequence showing cellular protein interactions. For the entire sequence, see clips K003/3837 to K003/3831.