Time: 11:00-12:00 PM

Location: Augsburg University, Foss Center, Hoversten Chapel

HOW MEMBRANES HELP CELLS DO THEIR JOBS

In the Middle Ages, cities were protected and defined by their walls. Likewise, in our bodies, cells and many of their sub-compartments are surrounded by membranes. However, instead of being solid and rigid like a stone wall, the membranes of cells are soft and dynamic. The building blocks of the membranes – the lipids and proteins – rapidly exchange places with their neighbors. Moreover, cells are constantly making new or different types of building blocks and inserting them into their membranes.

In her 2023 Sverdrup Visiting Scientist lectures, Sarah Keller, a professor at the University of Washington, will discuss how the dynamicism of membranes can be both a bane and a boon for cells. Very soft and dynamic membranes can rip or disintegrate. This would have been a problem for the most ancient cells on the Earth. On the other hand, movement of lipids within membranes can help cells react to their environment. This is a huge advantage for modern cells every day.

PROTOCELLS ON THE EARLY EARTH

The earliest versions of cells on Earth could have been very simple: a membrane that encloses molecules to encode information, like DNA, and to perform tasks, like proteins. However, the very simplest membranes are typically not stable in salty environments like oceans. How could those early cells have survived?

In the lecture, “Stabilizing fragile membranes on the early Earth”, Keller will explain that small building blocks of DNA and proteins can interact with membranes, stabilizing them. In turn, these interactions have the potential to concentrate the building blocks on the surface of the membrane, helping them link up into larger molecules capable of other important jobs.