Abstract
Yan Levin: „A tale of supermagnets, superconductors and ion channels”
Universidade Federal do Rio Grande do Sul
Ion channels are water filled holes which facilitate exchange of
electrolyte between the exterior and interior of a cell. Pores are
formed by specic proteins embedded into the phospholipid membrane.
Depending on the conformation of the protein, the pore can be open
or closed. In order to function properly the channel has to conduct
thousands of ions in a period of few milliseconds. Considering that
the channel passes through a phospholipid membrane which has a very
low dielectric constant and is very narrow, resulting in large
potential energy barriers, it is fascinating to contemplate how
Natures manages to perform this amazing task. In this talk I will
present an analytically solvable model which allows us to explicitly
study the electrodynamics of ion transport through a channel [1].
Along the way I will also discuss a beautiful demonstration of
Lenz's and Faraday's laws, which can be easily adopted to any
electricity and magnetism course [2]. Finally, the dynamics of ion
transport through a channel will be compared and contrasted to the
dynamics of a magnet moving through a superconducting pipe [3].
[1] Y. Levin, Electrostatics of ions inside nanopores and
trans-membrane channels, Europhys. Lett. 76, 163 (2006)
[2] Y. Levin, F. L. da Silveira, and F.B. Rizzato Electromagnetic
braking: a simple quantitative model,Am. J. Phys. 74, 815 (2006)
[3] Y. Levin and F.B. Rizzato Superconducting pipes and levitating
magnets, Phys. Rev.E74, 066605 (2006)