Question 1

In transportation within neurons, which direction is retrograde? Which direction is anterograde?

Accepted Answer

The answer of In transportation within neurons, which direction is...

Question 2

Why does the Na+ conductance decrease after a short time?

Accepted Answer

A)  The channels close. 
B)  The cell reaches ENa. 
C)  The Na+ channels inactivate. 
D)  The K+ channels start to open.

Question 3

Which membrane proteins require ATP to move ions across the membrane? Choose all that apply.

Accepted Answer

A)  Symporters 
B)  Pumps 
C)  Antiporters 
D)  Ion channels

Question 4

What does 'local protein translation' mean in neurons?

Accepted Answer

A)  Proteins are synthesized only in the nucleus. 
B)  Proteins are synthesized only in the cell body. 
C)  Proteins can be synthesized in dendrites. 
D)  Proteins can be synthesized by a neighboring neuron.

Question 5

What kinds of organelles have been localized to dendrites?

Accepted Answer

A)  Polyribosomes 
B)  ER 
C)  Golgi 
D)  All of the above 
E)  None of these are located in dendrites.

Question 6

How do Na⁺ and K⁺ ion channel structures allow them to detect changes in voltage across the membrane? Note: Questions 2-42 and 2-43 refer to the data in Figure Q2-42. These questions may be used independently or as a group.

Accepted Answer

The answer of How do Na⁺ and K⁺ ion channel...

Question 7

Why are action potentials usually generated at the axon hillock in vertebrate neurons?

Accepted Answer

A)  There is a high concentration of Na+ channels. 
B)  There is a high concentration of K+ channels. 
C)  This is the point at which most synaptic contacts are made. 
D)  It is located at the beginning of the axon.

Question 8

In order to understand how currents move during an axon potential Hodgkin and Huxley used the voltage clamp technique. Why was this technique so important? Choose all that apply.

Accepted Answer

A)  It allowed the investigators to measure ions moving across single channels. 
B)  It prevented the change in membrane potential associated with ions flowing across the membrane. 
C)  It allowed them to calculate the conductance of the individual ions. 
D)  It showed that currents vary with voltage and time.

Question 9

In the cochlea of the ear sounds waves are turned into electrical signals through special cells called hair cells. When a wave travels through the cochlea it moves the 'hairs' and opens ion channels that are permeable to K⁺ and Ca²⁺. These 'hairs' are in a fluid that has a very high K⁺ concentration compared to the inside of the cell. A. When the ion channels open, in what direction do K⁺ ions flow and why? B. Based on this relative concentration difference of K⁺, what do you predict the equilibrium potential for K⁺ will be: positive, negative or zero?

Accepted Answer

The answer of In the cochlea of the ear sounds...

Question 10

What helps maintain the ion concentration across the membrane of neurons?

Accepted Answer

A)  The driving force for any ion 
B)  Na+/K+ ATPase 
C)  Leak K+ channels 
D)  Leak Na+ channels

Question 11

If myelin makes action conduction velocity faster, why are axons not completely covered with myelin? That is, what would happen to the electrical signal if the axon was completely covered in myelin and had no Nodes of Ranvier?

Accepted Answer

The answer of If myelin makes action conduction velocity faster,...

Question 12

Which membrane proteins use the electrochemical gradient to move ions across the membrane? Choose all that apply.

Accepted Answer

A)  Symporters 
B)  Pumps 
C)  Antiporters 
D)  Ion channels

Question 13

For each labeled point (A-D) on the action potential shown in Figure Q2-34, state whether the conductance through voltage-dependent Na⁺ and K⁺ channels is low, high, or no conductance. Explain. [Note: For this answer, ignore conductance through leak channels.] Figure Q2-34

Accepted Answer

The answer of For each labeled point (A-D) on the...

Question 14

In Figure Q2-42, amino acids 6-46 were removed from the ShB channel through mutagenesis.
A. What happened to the single channel response?
B. When the ShB peptide (the first 20 amino acids of the ShB protein) was added to the ShBΔ6-46 protein, what happened to the single channel response and what does that tell you about the function of the first 20 amino acids?

Accepted Answer

The answer of In Figure Q2-42, amino acids 6-46 were...

Question 15

What is the function of exocytosis? Choose all that are correct.

Accepted Answer

A)  To take proteins to the plasma membrane 
B)  To take proteins away from the plasma membrane 
C)  Potential degradation of proteins 
D)  To secrete proteins from the cell

Question 16

Proteins that function in the cytoplasm and nucleus are synthesized in/on which organelle?

Accepted Answer

A)  Free ribosomes 
B)  Endoplasmic reticulum 
C)  Golgi apparatus 
D)  Nucleus

Question 17

Match between columns
                        Premises: movement of ions
membrane
concentration gradient
ion channel

Accepted Answer

The Answer of Current and Capacitor and Battery and Resistor is...

Question 18

What is the 'driving force'?

Accepted Answer

A)  The concentration gradient 
B)  The conductance of an ion 
C)  The equilibrium potential for an ion 
D)  The difference between the membrane potential and equilibrium potential

Question 19

The equilibrium potential for any ion is the point at which two forces/gradients balance each other. What are the two forces/gradients?

Accepted Answer

The answer of The equilibrium potential for any ion is...

Question 20

The brains of patients with Alzheimer's disease show degradation of microtubule function, in part from over-phosphorylation of the microtubule-associated protein, tau. What might happen to neurons when microtubule function is disrupted?

Accepted Answer

The answer of The brains of patients with Alzheimer's disease...

Exam 2: Signaling Within Neurons

In transportation within neurons, which direction is retrograde? Which direction is anterograde?

Why does the Na⁺ conductance decrease after a short time?

Which membrane proteins require ATP to move ions across the membrane? Choose all that apply.

What does 'local protein translation' mean in neurons?

What kinds of organelles have been localized to dendrites?

How do Na⁺ and K⁺ ion channel structures allow them to detect changes in voltage across the membrane? Note: Questions 2-42 and 2-43 refer to the data in Figure Q2-42. These questions may be used independently or as a group.

Why are action potentials usually generated at the axon hillock in vertebrate neurons?

In order to understand how currents move during an axon potential Hodgkin and Huxley used the voltage clamp technique. Why was this technique so important? Choose all that apply.

What helps maintain the ion concentration across the membrane of neurons?

If myelin makes action conduction velocity faster, why are axons not completely covered with myelin? That is, what would happen to the electrical signal if the axon was completely covered in myelin and had no Nodes of Ranvier?

Which membrane proteins use the electrochemical gradient to move ions across the membrane? Choose all that apply.

For each labeled point (A-D) on the action potential shown in Figure Q2-34, state whether the conductance through voltage-dependent Na⁺ and K⁺ channels is low, high, or no conductance. Explain. [Note: For this answer, ignore conductance through leak channels.] Figure Q2-34

What is the function of exocytosis? Choose all that are correct.

Proteins that function in the cytoplasm and nucleus are synthesized in/on which organelle?

Match each representative electrical component with its equivalent in a neuron.

What is the 'driving force'?

The equilibrium potential for any ion is the point at which two forces/gradients balance each other. What are the two forces/gradients?

The brains of patients with Alzheimer's disease show degradation of microtubule function, in part from over-phosphorylation of the microtubule-associated protein, tau. What might happen to neurons when microtubule function is disrupted?

Exam 2: Signaling Within Neurons

In transportation within neurons, which direction is retrograde? Which direction is anterograde?

Why does the Na+ conductance decrease after a short time?

Which membrane proteins require ATP to move ions across the membrane? Choose all that apply.

What does 'local protein translation' mean in neurons?

What kinds of organelles have been localized to dendrites?

How do Na+ and K+ ion channel structures allow them to detect changes in voltage across the membrane? Note: Questions 2-42 and 2-43 refer to the data in Figure Q2-42. These questions may be used independently or as a group.

Why are action potentials usually generated at the axon hillock in vertebrate neurons?

In order to understand how currents move during an axon potential Hodgkin and Huxley used the voltage clamp technique. Why was this technique so important? Choose all that apply.

What helps maintain the ion concentration across the membrane of neurons?

If myelin makes action conduction velocity faster, why are axons not completely covered with myelin? That is, what would happen to the electrical signal if the axon was completely covered in myelin and had no Nodes of Ranvier?

Which membrane proteins use the electrochemical gradient to move ions across the membrane? Choose all that apply.

For each labeled point (A-D) on the action potential shown in Figure Q2-34, state whether the conductance through voltage-dependent Na+ and K+ channels is low, high, or no conductance. Explain. [Note: For this answer, ignore conductance through leak channels.] Figure Q2-34

What is the function of exocytosis? Choose all that are correct.

Proteins that function in the cytoplasm and nucleus are synthesized in/on which organelle?

Match each representative electrical component with its equivalent in a neuron.

What is the 'driving force'?

The equilibrium potential for any ion is the point at which two forces/gradients balance each other. What are the two forces/gradients?

The brains of patients with Alzheimer's disease show degradation of microtubule function, in part from over-phosphorylation of the microtubule-associated protein, tau. What might happen to neurons when microtubule function is disrupted?

Why does the Na⁺ conductance decrease after a short time?

How do Na⁺ and K⁺ ion channel structures allow them to detect changes in voltage across the membrane? Note: Questions 2-42 and 2-43 refer to the data in Figure Q2-42. These questions may be used independently or as a group.

For each labeled point (A-D) on the action potential shown in Figure Q2-34, state whether the conductance through voltage-dependent Na⁺ and K⁺ channels is low, high, or no conductance. Explain. [Note: For this answer, ignore conductance through leak channels.] Figure Q2-34