Neuroscience exam 2 slide 13

How does large changes in membrane potential caused by?

small change in ionic concentrations-the number of ions that need to move to generate a potential is very small -concentrations remain essentially constant

How to determine structure of K+ channel?

by X-ray crystallography-negatively charged amino acid around pore which attract positive ions

Process of K+ ion to enter selectivity filter .

K+ ion must lose all water molecules to enter -oxygen atoms in selectivity filter spaced perfectly to serve as replacement foroxygen atoms in water molecules stripped off

How does Na+ ion do in selectivity filter?

Na+ ion can not enter, even though it's smaller -oxygen atoms in selectivity filter too far away to compensate for energy loss of water molecules