CBNS/ STUDY GUIDE 5-6, STUDY GUIDE 3-4, STUDY GUIDE 1-2 QUESTIONS AND ANSWERS, RATED A+/

CBNS/ STUDY GUIDE 5-6, STUDY GUIDE 3-4, STUDY GUIDE 1-2 QUESTIONS AND ANSWERS, RATED A+/ The Nernst Equation is used to predict: - -The equilibrium potential of a single membrane permeant ion The Goldman Equation is used to predict: - -The equilibrium potential of a single membrane-permeant ion The contribution of multiple permeant ions to Em Consider the frog muscle study published by Hodgkin and Horowicz (1959) that was presented in Lecture 5. Doubling [K]o from 10 mM to 20 mM would have the following effect on Em: - -depolarization Given what you now know about the squid giant axon and the NCX (Na/Ca Exchanger), what effect(s) would you predict as a consequence of decreasing [Na]o? (check all possible answers) - -Depolarize the cell Reduce the amplitude of action potential Increase intracellular Ca Concentration The Steady State Equation is used: - -All of the Above ( to predict Em, to predict the contribution of Na/K ATPase to Em, to predict the contribution of multiple membranepermeant ions to Em) Predict the resting potential (Em) for a neuron, where [K]i = 95 mM, [K]o = 5 mM, [Na]in= 15 mM, [Na]o= 140 mM, at room temperature (T=298oK), with R=8.3 coul-volts/deg-mol, F = 96,500 coul/mol. Assume that the Na permeability of the cell membrane is 1/50 that of the K permeability, that the neuron is bathed in ouabain, and that chloride ions are in equilibrium and hence do not contribute to Em. - --64 mv Refer to the previous scenario (Question 6). Predict the value of Em following removal of ouabain from the bathing medium. - --67 m