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Membrane Biophysics Calculations Week 5: 1. After a particular step depolarization in Hodgkin and Huxley’s squid giant axon, the parameter n follows the curve, n = 0.891 – 0.376e –t/1.7 msec t is in the msec gK (this is maximum conductance; g bar K) = 24.3 ms/cm2 remember that gK = gKn4 (potassium conductance = maximum potassium conductance (g bar) times n to the fourth power) a. Plot gK as a function of time, using 1 msec steps for 10 msec. b. What is the approximate steady-state gK (i.e. gK ∞)? c. Knowing that gNa = gNa (max) m3h, using the following calculated parameters, m = 0.963 (1- e-t/0.252 msec) h = 0.605 e –t/0.84 msec t is in the msec gNa (maximum) = 70.7 ms/cm2 Plot gNa on the same graph as in a using 0.5 msec time steps for 5 msec. d. What is the approximate peak gNa that is reached? e. Ignoring the leak current, what would be the total current evoked (Ii) in an experiment where introduced voltage-step was Vc = -20 mV from a Vh = -80 mV. Answers: Since many of the componen...