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Short stories in membrane biophysics of how complex behavior arises from minimal components

Event Details

Event Dates: 

Friday, October 23, 2015 - 4:00pm

Seminar Location: 

  • JILA Auditorium

Speaker Name(s): 

Sarah Keller

Speaker Affiliation(s): 

University of Washington
Seminar Type/Subject

Scientific Seminar Type: 

  • Phys Chem/Chem Phys Seminar

Event Details & Abstract: 

This talk will briefly summarize a few of our laboratory’s recent research themes that were inspired by biological questions. Asking how sub-micron composition fluctuations might arise in a lipid membrane near a critical point led to our determination of the membrane’s effective critical dynamic exponent -- the first successful systematic measurement of this fundamental physical parameter in any 2-dimensional Ising system with conserved order parameter, whether biological or not (Honerkamp-Smith et al. PRL 2012). Far from the critical point, lipid membranes can demix into coexisting liquid phases. Asking how groups of lipids diffuse within a membrane led to our measurement of growth exponents for membrane domains (Stanich et al. 2013). Asking whether tension in a membrane can make those domains appear or disappear led to our quantification of how tension changes miscibility temperatures (Portet et al. BJ 2012). Last, simply for fun, asking how molecules on the early Earth assemble into protocells of RNA surrounded by a membrane led to our discovery that the building blocks of RNA (nucleobases and sugars) bind to fatty-acid membranes and enhance the membrane’s stability (Black et al. PNAS 2013). These interactions could have plausibly contributed to the emergence of the first protocells on the early Earth (and eventually to physical chemists and chemical physicists).