HTHS 1111 Unit 11 to Unit 15 Questions and Answers
1. What do the red and grey triangle on the right side of the diagram repre- sent?: the
gradients of potassium and sodium: their direction of move ment if
to move allowed
2. When a potassium resting (leakage) channel opens, which way will potas- sium move?
(Assume the membrane potential is close to the neuron's resting potential).: out of the neuron
3. Ion channel in neurons come in four types: ligand-gated, resting (leakage), signal-gated, and
voltage-gated. Which of these categories includes a protein that selectively permits the passage of
potassium ions?
- ligand-gated
- resting (leakage)
- signal-gated
- voltage-gated
- All of the above: All of the above
4. This protein operates continuously to maintain the normal concentration of ions inside and
outside neurons:: sodium/potassium ATPase (Na+/K+ "pump")
5. What region is intracellular?
-1
- 2: 2
6. If only protein channel "4" were opened, and every other channel closed, the were
membrane potential would be expected to be:
- near the potassium equilibrium potential
- near the sodium equilibrium potential
- zero: near the potassium equilibrium potential
7. In the membrane of most neurons, there are about fourteen times as
protein as there is as many . many
- 3, 4
- 4, 3: 4, 3
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, HTHS 1111 Unit 11 to Unit 15 Questions and Answers
8. In the theoretical neuron shown here, with equal numbers of protein "3" and protein "4",
the membrane potential would be expected to be:
- midway between the sodium and potassium equilibrium potentials
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, HTHS 1111 Unit 11 to Unit 15 Questions and Answers
- near the sodium equilibrium potential
- near the potassium equilibrium potential
- near the chloride equilibrium potential: midway between the sodium a sium nd
equilibrium potentials potas-
9. What element of the voltage-gated sodium channel is represe three positive nted by
signs ("+++")?: membrane voltage sensor the
10. Which of these drawings represent the open state of the voltage-gated sodium channel?
- 1 only
- 2 only
- 3 only
-1+2
-2+3
-1+3
- all of them (1 + 2 + 3): 2 only
11. Note that near the polar head groups of the membrane phos molecules, therepholipid
is a row of either +s or -s. What do these symbols represent?-
: membrane voltage
12. Action potentials arise from transient (i.e. brief on and off activation of):: -
voltage-gated channel
13.This diagram shows that, as we move away from the locatio stimulus, the n of the
voltage in the neuron:: decreases
14.In a wire, current is carried by a moving front of electrons. In current is a neuron,
carried by (Hint: read the legend in the top panel):: po tassium
ions
Contact for help with assignments .
1. What do the red and grey triangle on the right side of the diagram repre- sent?: the
gradients of potassium and sodium: their direction of move ment if
to move allowed
2. When a potassium resting (leakage) channel opens, which way will potas- sium move?
(Assume the membrane potential is close to the neuron's resting potential).: out of the neuron
3. Ion channel in neurons come in four types: ligand-gated, resting (leakage), signal-gated, and
voltage-gated. Which of these categories includes a protein that selectively permits the passage of
potassium ions?
- ligand-gated
- resting (leakage)
- signal-gated
- voltage-gated
- All of the above: All of the above
4. This protein operates continuously to maintain the normal concentration of ions inside and
outside neurons:: sodium/potassium ATPase (Na+/K+ "pump")
5. What region is intracellular?
-1
- 2: 2
6. If only protein channel "4" were opened, and every other channel closed, the were
membrane potential would be expected to be:
- near the potassium equilibrium potential
- near the sodium equilibrium potential
- zero: near the potassium equilibrium potential
7. In the membrane of most neurons, there are about fourteen times as
protein as there is as many . many
- 3, 4
- 4, 3: 4, 3
Contact for help with assignments .
, HTHS 1111 Unit 11 to Unit 15 Questions and Answers
8. In the theoretical neuron shown here, with equal numbers of protein "3" and protein "4",
the membrane potential would be expected to be:
- midway between the sodium and potassium equilibrium potentials
Contact for help with assignments .
, HTHS 1111 Unit 11 to Unit 15 Questions and Answers
- near the sodium equilibrium potential
- near the potassium equilibrium potential
- near the chloride equilibrium potential: midway between the sodium a sium nd
equilibrium potentials potas-
9. What element of the voltage-gated sodium channel is represe three positive nted by
signs ("+++")?: membrane voltage sensor the
10. Which of these drawings represent the open state of the voltage-gated sodium channel?
- 1 only
- 2 only
- 3 only
-1+2
-2+3
-1+3
- all of them (1 + 2 + 3): 2 only
11. Note that near the polar head groups of the membrane phos molecules, therepholipid
is a row of either +s or -s. What do these symbols represent?-
: membrane voltage
12. Action potentials arise from transient (i.e. brief on and off activation of):: -
voltage-gated channel
13.This diagram shows that, as we move away from the locatio stimulus, the n of the
voltage in the neuron:: decreases
14.In a wire, current is carried by a moving front of electrons. In current is a neuron,
carried by (Hint: read the legend in the top panel):: po tassium
ions
Contact for help with assignments .
