Question 1
For all of these gradient questions, pick either into the cell or out of the cell for your answer; assume that the cell is at rest. Try to do this without looking at your notes to see if you can remember this. To help yourself, have some paper and a pencil handy, draw a cell outline, and work through each ion as you go through this question.
the calcium concentration gradient
the calcium electrical gradient into the cell
the potassium concentration gradient
the potassium electrical gradient
the chloride concentration gradient
the chloride electrical gradient
the sodium concentration gradient
the sodium electrical gradient
the sodium electrochemical gradient
the potassium electrochemical gradient
All Answer Choices
A. into the cell
B. out of the cell
Question 2
Match each ion with the postsynaptic potential they can cause.
sodium ions
calcium ions
potassium ions
chloride ions
All Answer Choices
A. i.p.s.p.s
B. e.p.s.p.
Question 3
Most neurotransmitters fit into the protein category for the type of molecule they are, being either amino acids, modified amino acids, or small peptides.
Answer Choices:
True
False
Question 4
Order the electrochemical gradients on these four ions from the most inward to the most outward. Assume the cell these gradients apply to is at rest.
Answer Choices
sodium
calcium
potassium
chloride
Question 5
Put the following steps of the action potential in order.
Answer Choices
A cell depolarizes from rest to its threshold potential.
Sodium voltage-gated channels open.
Sodium voltage-gated channels and delayed rectifier channels are activated.
The neuron depolarizes quickly from above threshold toward a positive membrane potential.
The action potential reaches its peak depolarization.
Potassium delayed rectifiers begin to open and sodium voltage-gated channels begin to inactivate.
The membrane potential repolarizes.
Potassium delayed rectifiers all close and sodium voltage-gated channels de-inactivate to closed.
The membrane potential overshoots resting potential and hyperpolarizes.
The membrane potential returns to resting.
Question 6
Select the 4 answers that help explain why the resting potential of a cell is negative.
Answer Choices
There are some items that carry negative charges that are stuck inside the cell.
Electrical gradients on ions play no part in the resting potential.
Calcium ions can flow along their gradient any time.
Leak channels tend to keep the membrane potential low.
The sodium-potassium pump is only active when a cell is at rest.
The sodium-potassium pump pumps out more sodium ions than it retrieves potassium ions.
At rest, sodium channels are not open.
Sodium ions can flow along their gradient any time.
Question 7
Select whether each statement about voltage-gated channels is true or false.
A sodium voltage-gated channel that is inactivated can be opened.
A sodium voltage-gated channel that is closed can be opened.
A potassium delayed rectifier that is closed can be opened.
A potassium delayed rectifier, once opened, stays open until the cell is no longer depolarized.
A sodium voltage-gated channel, once opened, stays open until the cell is no longer depolarized. false
The refractory period is due to the behavior of the sodium voltage-gated channel.
A closed sodium voltage-gated channel can become inactivated from its closed condition.
Voltage-gated channels are responsible for e.p.s.p.s and i.p.s.p.s.
All Answer Choices
A. true
B. false
Question 8
Which of the following relate to e.p.s.p.s? Select 4 answers.
Answer Choices
they tend to occur directly on axons
they can be due to the opening of ligand-gated channels
they are all-or-none potentials
they are depolarizing
they can sum
they occur once and then their channels inactivate
they are graded potentials
only acetylcholine will cause them
they are hyperpolarizing
