BME 301 Homework #6 - Due 10 am on February 27, 2015
Gating variables
Time constants (ms)
Problem 2. Dependence of steady state gate variables and time constants as a function of
membrane voltage (Vm) in a squid axon is given in the figures below.
-60
-30
BME 101: Homework 1 Solutions
Problem 1. (+11 points possible)
a. Time constant:
(+1)
From the lecture notes:
(+1)
(+2) Graph:
b.
(+1) Time constant stays the same as in part a:
(+1)
(+2) Graph and explanation: Vm(t) would asymptote at a higher steady sta
BME 301L: Homework 3
Problem I. (5 points possible)
1) Donnan equilibrium occurs when: ENa+ = ECl- = EHCO3- =EK+
= 1.05
Use the ratio and the given concentrations to calculate the other concentrations.
Ion
K+
Na+
ClHCO3(+3 points)
Plasma
water
4.2 mM
151
BME 301 Homework #9 Due 10 am Friday April 3, 2015
Problem 1. Consider a myelinated nerve axon whose cross section is shown in the figure below. We
would like to study this axon using a program written for a non-myelinated axon. This will require
replacin
BME 301L Homework #9 Solutions
BME 101
Problem 1 (+8 points possible).
a) Consider analog circuit of one unit (ln and lsh) of the myelinated nerve:
Evaluate components:
, where
, where
is the surface area of the node
is the surface area of the myelinated
Due 10 am on Friday, April 10th, 2015.
BME301 Homework 10
Problem 1.
A forgetful professor measured the membrane potential of an infinite one-dimensional passive fiber in 3
configurations shown in figure below:
i)
ii)
-I0
re 0
rm, cm
iii)
re 0
rm, cm
+I0
BME301 Homework 11
Due 7 pm on Wednesday, April 22nd
Problem 1.
d. Assume now that hP = hN = h. Assume also that you can arbitrary move the two electrodes along
the z-axis, while having their distances from the fiber fixed (at h). What is the separation o
Recitation problems from the phase III of the class (04/20/2015):
Problem 1. Consider the idealized temporal waveform of a cardiac action potential in a mouse
Purkinje fiber (Figure 1). This action potential propagates with speed = 100 cm/sec in the negat
Recitation 2. March 23rd, 2015.
Problem 1. A mammalian neuron is of Hodgkin-Huxley type. Dependences of steady state gate
variables on transmembrane potential are shown in the figure left below. Equilibrium potentials for Na,
K and leakage channels are re
4. Hodgkin and Huxley rst performed their experiment in the normal sea water; the
Nernst potential for sodium was 57 mV. Later, they replaced some of the extracellular
sodium by choline. At Vclamp = 10 mV, this change totally abolished sodium current.
Com
BME 301 Homework #8 - Due
March 20, 201
Problem 1. An infinitely long cylindrical bath with radius is made to be used in the H-H type
electrophysiological experiments. Assume that in the center of the bath you can readily swap different
infinite cylindric
BME 301 Homework #7 - Due 5 pm on Friday March 6, 2015
Problem 1. A nerve cell is space-clamped. Assume that
,
,
and that the gating variables behave as shown in Fig. 1a. A small subthreshold current pulse is injected intracellularly and the response is s