Question 1

Why is a high resistance seal (a "giga-seal") required to perform patch clamp recordings?

Accepted Answer

When ions move between the cell cytoplas

Question 2

The "cell-attached" patch clamp technique

Accepted Answer

A)  allows the experimenter to easily change the solution bathing the inside surface of the membrane patch during the recording and study the activity of single voltage-gated channel currents. 
B)  allows the experimenter to easily change the solution bathing the outside surface of the membrane patch during the recording and study the activity of single voltage-gated channel currents. 
C)  does not allow the experimenter to change the solution on either side of the membrane patch, but you can study the activity of single voltage-gated currents. 
D)  allows the experimenter to easily change the solution bathing the inside surface of the membrane patch during the recording and study the summed activity of all voltage-gated channels in the cell (macroscopic current). 
E)  allows the experimenter to easily change the solution bathing the outside surface of the membrane patch during the recording and study the summed activity of all voltage-gated channels in the cell (macroscopic current). 
A)  allows the experimenter to easily change the solution bathing the inside surface of the membrane patch during the recording and study the activity of single voltage-gated channel currents. 
B)  allows the experimenter to easily change the solution bathing the outside surface of the membrane patch during the recording and study the activity of single voltage-gated channel currents. 
C)  does not allow the experimenter to change the solution on either side of the membrane patch, but you can study the activity of single voltage-gated currents. 
D)  allows the experimenter to easily change the solution bathing the inside surface of the membrane patch during the recording and study the summed activity of all voltage-gated channels in the cell (macroscopic current). 
E)  allows the experimenter to easily change the solution bathing the outside surface of the membrane patch during the recording and study the summed activity of all voltage-gated channels in the cell (macroscopic current).

Question 3

The conductance of a channel depends on which two factors?

Accepted Answer

A)  The voltage across the plasma membrane and the concentration of ions 
B)  Channel permeability and the voltage across the plasma membrane 
C)  The mean open time of the channel and the concentration of ions 
D)  Channel permeability and the concentration of the ions 
E)  The mean open time of the channel and the channel permeability 
A)  The voltage across the plasma membrane and the concentration of ions 
B)  Channel permeability and the voltage across the plasma membrane 
C)  The mean open time of the channel and the concentration of ions 
D)  Channel permeability and the concentration of the ions 
E)  The mean open time of the channel and the channel permeability

Question 4

The equilibrium potential depends on

Accepted Answer

A)  the open state of the channel. 
B)  the ion concentrations on either side of the membrane. 
C)  the mechanism for ion permeation through the channel. 
D)  whether the channel is inactivated. 
E)  the number of pathways for current flux. 
A)  the open state of the channel. 
B)  the ion concentrations on either side of the membrane. 
C)  the mechanism for ion permeation through the channel. 
D)  whether the channel is inactivated. 
E)  the number of pathways for current flux.

Question 5

What is the diameter of the tip of a microelectrode?

Accepted Answer

A)  1-3 micrometers 
B)  1 millimeter 
C)  10 micrometers 
D)  100 micrometers 
E)  less than 0.5 micrometers 
A)  1-3 micrometers 
B)  1 millimeter 
C)  10 micrometers 
D)  100 micrometers 
E)  less than 0.5 micrometers

Question 6

Hyperpolarization occurs when the membrane potential

Accepted Answer

A)  does not change. 
B)  displays rectification. 
C)  becomes more negative. 
D)  changes direction. 
E)  becomes more positive. 
A)  does not change. 
B)  displays rectification. 
C)  becomes more negative. 
D)  changes direction. 
E)  becomes more positive.

Question 7

Conductance characteristics of a channel can be specified precisely by determining

Accepted Answer

A)  a slope conductance. 
B)  a chord conductance. 
C)  a complete current-voltage relation and by specifying the ionic conditions under which it was obtained. 
D)  an averaging of the slope conductance and the chord conductance. 
E)  the driving force. 
A)  a slope conductance. 
B)  a chord conductance. 
C)  a complete current-voltage relation and by specifying the ionic conditions under which it was obtained. 
D)  an averaging of the slope conductance and the chord conductance. 
E)  the driving force.

Question 8

Based on the Nernst equation, if the concentration of sodium outside was 130 mM and the concentration of sodium in the cytoplasm was 12 mM, what is the sodium equilibrium potential?

Accepted Answer

A)  -85 mV 
B)  -30 mV 
C)  0 mV 
D)  +30 mV 
E)  +60 mV 
A)  -85 mV 
B)  -30 mV 
C)  0 mV 
D)  +30 mV 
E)  +60 mV

Question 9

The "inside-out" patch clamp technique

Accepted Answer

A)  allows the experimenter to easily change the solution bathing the inside surface of the membrane patch during the recording and study the activity of single voltage-gated channel currents. 
B)  allows the experimenter to easily change the solution bathing the outside surface of the membrane patch during the recording and study the activity of single voltage-gated channel currents. 
C)  does not allow the experimenter to change the solution on either side of the membrane patch, but you can study the activity of single voltage-gated currents. 
D)  allows the experimenter to easily change the solution bathing the inside surface of the membrane patch during the recording and study the summed activity of all voltage-gated channels in the cell (macroscopic current). 
E)  allows the experimenter to easily change the solution bathing the outside surface of the membrane patch during the recording and study the summed activity of all voltage-gated channels in the cell (macroscopic current). 
A)  allows the experimenter to easily change the solution bathing the inside surface of the membrane patch during the recording and study the activity of single voltage-gated channel currents. 
B)  allows the experimenter to easily change the solution bathing the outside surface of the membrane patch during the recording and study the activity of single voltage-gated channel currents. 
C)  does not allow the experimenter to change the solution on either side of the membrane patch, but you can study the activity of single voltage-gated currents. 
D)  allows the experimenter to easily change the solution bathing the inside surface of the membrane patch during the recording and study the summed activity of all voltage-gated channels in the cell (macroscopic current). 
E)  allows the experimenter to easily change the solution bathing the outside surface of the membrane patch during the recording and study the summed activity of all voltage-gated channels in the cell (macroscopic current).

Question 10

What is advantage of using a "perforated patch" recording technique instead of a traditional "whole-cell recording" technique?

Accepted Answer

In traditional whole-cell recording, sub

Question 11

Describe the methods for forming a whole-cell patch clamp recording.

Accepted Answer

First, the experimenter touches the patc

Question 12

Eyring rate theory models of ion permeation

Accepted Answer

A)  are based on ion diffusion only. 
B)  are based on the contribution of electrostatic charges in the pore only on the rate of flux. 
C)  are based on the contribution of electrostatic charges in the pore only on ion selectivity. 
D)  incorporate the effects of electrostatic charges in the pore on ion selectivity and the rate of flux. 
E)  incorporate the effects of electrostatic charges in the pore and the voltage across the membrane. 
A)  are based on ion diffusion only. 
B)  are based on the contribution of electrostatic charges in the pore only on the rate of flux. 
C)  are based on the contribution of electrostatic charges in the pore only on ion selectivity. 
D)  incorporate the effects of electrostatic charges in the pore on ion selectivity and the rate of flux. 
E)  incorporate the effects of electrostatic charges in the pore and the voltage across the membrane.

Question 13

Even though channels have a mean open time, what causes the measured openings of the channel to vary randomly around this mean?

Accepted Answer

All large molecules, like proteins, are

Question 14

Using the Nernst equation, what would you calculate the equilibrium potential for the sodium ion to be if the concentration of sodium outside was 130 mM, and the concentration of sodium in the cytoplasm was 12 mM?

Accepted Answer

According to the Nernst equation: E_Na = 58

Question 15

When membrane potential is at the equilibrium potential for an ion, there is/are

Accepted Answer

A)  an inward net movement of ions. 
B)  no net movement of ions across the membrane (equal in and out). 
C)  an outward net movement of ions. 
D)  no movement of ions in either direction (in or out). 
E)  equal numbers of the permeant ion inside and outside the cell. 
A)  an inward net movement of ions. 
B)  no net movement of ions across the membrane (equal in and out). 
C)  an outward net movement of ions. 
D)  no movement of ions in either direction (in or out). 
E)  equal numbers of the permeant ion inside and outside the cell.

Question 16

The channel "gate" is best described as a part of the channel

Accepted Answer

A)  pore that contains a ring of uncharged residues that interact with specific ions. 
B)  pore that contains a ring of charged residues that interact with specific ions. 
C)  structure that can change shape to either close or open the access through the channel pore. 
D)  structure that responds directly to changes in voltage across the plasma membrane. 
E)  pore that aids in stripping water from hydrated ions before they enter the pore. 
A)  pore that contains a ring of uncharged residues that interact with specific ions. 
B)  pore that contains a ring of charged residues that interact with specific ions. 
C)  structure that can change shape to either close or open the access through the channel pore. 
D)  structure that responds directly to changes in voltage across the plasma membrane. 
E)  pore that aids in stripping water from hydrated ions before they enter the pore.

Question 17

What is an anion?

Accepted Answer

A)  A negatively charged particle 
B)  An uncharged particle 
C)  A positively charged particle 
D)  A negatively charged amino acid residue 
E)  A positively charged amino acid residue 
A)  A negatively charged particle 
B)  An uncharged particle 
C)  A positively charged particle 
D)  A negatively charged amino acid residue 
E)  A positively charged amino acid residue

Question 18

Channels can be induced to open based on

Accepted Answer

A)  only the voltage across the membrane. 
B)  only the effects of membrane stretch on the channel. 
C)  only the effects of ligand binding to the channel. 
D)  only the effects of either voltage across the membrane, membrane stretch, or ligand binding, but not more than one of these. 
E)  the effects of voltage across the membrane, membrane stretch, ligand binding, or a mixture of these influences. 
A)  only the voltage across the membrane. 
B)  only the effects of membrane stretch on the channel. 
C)  only the effects of ligand binding to the channel. 
D)  only the effects of either voltage across the membrane, membrane stretch, or ligand binding, but not more than one of these. 
E)  the effects of voltage across the membrane, membrane stretch, ligand binding, or a mixture of these influences.

Question 19

A "rectifiying" channel

Accepted Answer

A)  does not conduct ions because the pore is closed. 
B)  conducts ions equally in both directions. 
C)  is better at conducting ions in one direction than the other. 
D)  inactivates rapidly. 
E)  deactivates rapidly. 
A)  does not conduct ions because the pore is closed. 
B)  conducts ions equally in both directions. 
C)  is better at conducting ions in one direction than the other. 
D)  inactivates rapidly. 
E)  deactivates rapidly.

Question 20

The "outside-out" patch clamp technique

Accepted Answer

A)  allows the experimenter to easily change the solution bathing the inside surface of the membrane patch during the recording and study the activity of single voltage-gated channel currents. 
B)  allows the experimenter to easily change the solution bathing the outside surface of the membrane patch during the recording and study the activity of single voltage-gated channel currents. 
C)  does not allow the experimenter to change the solution on either side of the membrane patch, but you can study the activity of single voltage-gated currents. 
D)  allows the experimenter to easily change the solution bathing the inside surface of the membrane patch during the recording and study the summed activity of all voltage-gated channels in the cell (macroscopic current). 
E)  allows the experimenter to easily change the solution bathing the outside surface of the membrane patch during the recording and study the summed activity of all voltage-gated channels in the cell (macroscopic current). 
A)  allows the experimenter to easily change the solution bathing the inside surface of the membrane patch during the recording and study the activity of single voltage-gated channel currents. 
B)  allows the experimenter to easily change the solution bathing the outside surface of the membrane patch during the recording and study the activity of single voltage-gated channel currents. 
C)  does not allow the experimenter to change the solution on either side of the membrane patch, but you can study the activity of single voltage-gated currents. 
D)  allows the experimenter to easily change the solution bathing the inside surface of the membrane patch during the recording and study the summed activity of all voltage-gated channels in the cell (macroscopic current). 
E)  allows the experimenter to easily change the solution bathing the outside surface of the membrane patch during the recording and study the summed activity of all voltage-gated channels in the cell (macroscopic current).

Exam 4: Ion Channels and Signaling

Why is a high resistance seal (a "giga-seal") required to perform patch clamp recordings?

The "cell-attached" patch clamp technique

The conductance of a channel depends on which two factors?

The equilibrium potential depends on

What is the diameter of the tip of a microelectrode?

Hyperpolarization occurs when the membrane potential

Conductance characteristics of a channel can be specified precisely by determining

Based on the Nernst equation, if the concentration of sodium outside was 130 mM and the concentration of sodium in the cytoplasm was 12 mM, what is the sodium equilibrium potential?

The "inside-out" patch clamp technique

What is advantage of using a "perforated patch" recording technique instead of a traditional "whole-cell recording" technique?

Describe the methods for forming a whole-cell patch clamp recording.

Eyring rate theory models of ion permeation

Even though channels have a mean open time, what causes the measured openings of the channel to vary randomly around this mean?

Using the Nernst equation, what would you calculate the equilibrium potential for the sodium ion to be if the concentration of sodium outside was 130 mM, and the concentration of sodium in the cytoplasm was 12 mM?

When membrane potential is at the equilibrium potential for an ion, there is/are

The channel "gate" is best described as a part of the channel

What is an anion?

Channels can be induced to open based on

A "rectifiying" channel

The "outside-out" patch clamp technique

Principles of Signaling and Organization

Signaling in the Visual System

Functional Architecture of the Visual Cortex

Structure of Ion Channels

Ionic Basis of the Resting Potential

Ionic Basis of the Action Potential

Electrical Signaling in Neurons

Ion Transport Across Cell Membranes

Properties and Functions of Neuroglial Cells

Mechanisms of Direct Synaptic Transmission

Indirect Mechanisms of Synaptic Transmission

Release of Neurotransmitters

Neurotransmitters in the Central Nervous System

Transmitter Synthesis, Storage, Transport, and Inactivation

Synaptic Plasticity

The Molecular and Cellular Biology of Synaptic Plasticity

Mechanisms of Extrasynaptic Communication

Autonomic Nervous System

Walking, Flying, and Swimming: Cellular Mechanisms of Sensorimotor Behavior in Invertebrates

Sensory Transduction

Transduction and Transmission in the Retina

Touch, Pain, and Texture Sensation

Auditory and Vestibular Sensation

Constructing Perception

Initiation and Control of Coordinated Muscular Movements

Development of the Nervous System

Critical Periods in Sensory Systems

Regeneration and Repair of Synaptic Connections After Injury

Appendix

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