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In: Biology

Sodium and potassium ion channels have several negatively charged residues at the entry to the channel....

Sodium and potassium ion channels have several negatively charged residues at the entry to the channel. On what basis do K+ channels specifically select for K+ ions? (In other words, why dont K+ channels enable Na+ ions to cross the membrane?)

 

-ionic radius, Na+ is to small

-energy cost, it is to energetically costly to dehydrate Na+

-charge, Na is slightly more electronegative than K and does not interact with the channel carbonyl groups

-charge, Na is slightly less electronegative than K and does not interact with the channel carbonyl groups

-ionic radius, Na+ is too big

Solutions

Expert Solution

energy cost, it is too energetically costly to dehydrate Na+

ionic radius, Na+ is too small

gladiator answered 2 years ago
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