text: Yo, check it, let me break it down for you
  Ion conduction in K(+)-channels, that's what we do
  Concerted movements of K(+) in a single file
  Through a narrow pore, yeah, that's the style
  
  Permeation's driven by an incoming ion
  Knocking on the ones already inside, c'mon
  We need a balance of high-affinity binding
  And electrostatic repulsion, that's what we're finding
  
  K(+)-channels selective for K(+) over Na(+)
  But some conduct Na(+) without K(+), that's a fact
  Other ions can permeate, but with a moderate preference
  Unusual conduction features, it's intense
  
  We ran a computational study, extensive and deep
  Free energy profiles for ions, let me speak
  Translocation of alkali ions and their mixtures
  Rb(+) conductance slightly lower, no glitches
  
  Atomic level insights, we got it all mapped out
  Why Rb(+) conductance, yeah, it's in doubt
  K(+) and Rb(+) are different, no doubt about that
  But external Na(+) blocks K(+) currents, combat!
  
  We found the sites where Na(+) transport is hindered
  Energetically unfavorable, that's how it's rendered
  K(+)/Na(+) mixtures ain't gonna make the cut
  No equally spaced ion-binding sites, that's a shut
  
  So Na(+) gets excluded from the loaded channel
  Already filled with K(+), it's a hard battle
  That's the deal with ion conduction in K(+)-channels
  Free energy, translocation, it's all in these panels