| Comments |
"Ion channels
are classified first according to their ion selectivity for
permeant ions that pass through the channel. Thus,
channels selective for K+, Na+, Ca2+, Cl-, and H+ have
been identified in various cells of the body. Distinguishing
properties of an ion channel include the single channel
conductance (a measure of how many ions per
second can pass through the channel—typically for ion
channels this number is 10^6 or greater), how this conductance
is affected by the concentration of permeant
ions, the sequence of permeability or conductance for
different ions, the size of the channel judged from the
bulkiest permeant ion, and the “rectification” of the open
channel (favoring inward or outward movement of ions)." |