2009 Exam 2

# The data for the axon are as follows ion intra c e

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Unformatted text preview: ows: Ion [intra c e llula r] Na + 40 m M K+ Equilibrium p ote ntia l for ion 200 m M 59 m V ￿59 m V (a) 6 pts. For each ion, calculate its EXTRACELLULAR concentration at rest. Show your WORK at LEFT and write your FINAL ANSWER in the box at RIGHT. Be careful with UNITS: Na+ Wo rk a n s w e r (m M) V N a = (59 m V /z) ￿ log([N a]out/[N a]in) 400 m M 59 m V = ( 59 m V /1) × log([N a]out/[N a]in) 1 = lo g ([N a]out/4 0 m M) 1 0 = [N a]out/4 0 mM [N a]out = 4 0 m M × 1 0 = 4 0 0 m M K+ Wo rk a n s w e r (m M) V K = (59 m V /z) ￿ lo g ([K]out/[K]in) 20 m M ￿ 59 m V = (59 m V /1) ￿ lo g ([K]out/[K]in) ￿ 1 = lo g ([K ]out/2 0 0 m M) 1 0 ￿1 = [K ]out/ 2 0 0 m M [K ]out = 2 0 0 m M × 0 .1 = 2 0 m M -6- NAME: __________KEY________________ MIDTERM EXAM II BIOLOGY 231 19 October 2009 ________________________________________________________________________________ 4(b) 6 pts. Assuming that the resting membrane potential for the giant squid axon is ￿70 mV, calculate the ￿G for each ion. Show your WORK at lef...
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## This note was uploaded on 03/12/2012 for the course BIO 231 taught by Professor Hollenbeck during the Fall '11 term at Purdue.

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