MIDTERM EXAM Introduction to Neuroscience – Bio 3411 1999 1 ...

2
Midterm Exam
Introduction to Neuroscience – Bio 3411 (1999)
Name: _____________________________________
3) Which of the following is unimportant in establishing the membrane resting potential
a. The bulk concentrations of all impermeant ions.
b. The equilibrium potential for all permeable ions.
c. The intracellular concentration of potassium ion.
d. Membrane leak channels.
e. The sodium-potassium ATPase.
f. All of the above.
4) Using patch clamp technique:
a. Different channels can be distinguished according to their single channel
conductance.
b. Different channels can be distinguished according to their mean open time.
c. Different channels can be distinguished according to their inactivation properties.
d. Different channels can be distinguished according to their reversal potentials.
e. All of the above.
f. A, B & C only
5) The condition of Hyperkalemic Periodic Paralysis is a genetic disease caused by a
mutation in a voltage-gated sodium channel. However, it resembles “Hyperkalemia” a
condition where the bulk concentration of extracellular potassium is too high. Which of the
following is true:
1. The membrane resting potential in affected cells is too positive.
2. The condition could result from some sodium channels open at resting potentials.
3. A similar condition could result from a mutation that affects leak (K+ selective) channels.
4. All of the above.
5. 1 & 2 above.
6) Long QT syndrome shows a pattern of dominant inheritance because:
A. The mutant potassium channel gene suppresses the genetic expression of the cardiac sodium
channel.
B. Mutant potassium channel subunits form heteromultimers with wild-type subunits.
C. The mutant potassium channel gene shows dominant epistasis.
D. The mutant potassium channel shortens the duration of the cardiac action potential.
E. None of the above.