Creased, crumpled and odd-looking, we have trillions of these strange structures inside our bodies. These are cell membranes, biological bags that keep life-giving chemicals safe – and volatile ones separate – inside our cells. Each grey-coloured membrane pictured here (in a computer simulation) is being tugged about by red-coloured structural proteins attached to its surface. The proteins curve the membrane slightly, like poles embedded in the lining of a tent, pulling it into shape. These computer simulations show a variety of membrane shapes produced simply by increasing the number of virtual protein ‘poles’ and watching how their tug o’ war with the membrane resolves itself. As more proteins are attached (from top left to bottom right, here), the squirming membranes settle in different ways – even forming tube shapes similar to those found inside our cells (bottom right), where they have evolved to pipe chemicals from place to place.
Written by John Ankers
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.
BPoD is also available in Catalan at www.bpod.cat with translations by the University of Valencia.