Assertion: membrane's protein | /r/HasProperty | structural
Facets:
Source sentences:
text: Lipids are known to spontaneously form bilayered vesicles in water, and could have preceded RNA, but the first cell membranes could also have been produced by catalytic RNA, or even have required structural proteins before they could form.
text: The basal lamina is secreted by the cells of the epithelial tissue itself and contains proteins, glycoproteins, and collagen IV, a type of structural protein that forms sheets.