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Biol 320 Exam 3 Newest 2025/ 2026 Actual Exam
Complete Questions And Correct Answers ||VERIFIED
EXAM||(Verified Answers) |Already Graded A+||
LATEST EXAM UPDATE!!
Tight junctions found between the cells in our intestines
PREVENT
Small, non-polar molecules from using simple diffusion to
cross the plasma membrane
Membrane proteins from showing lateral movement
through the entire plasma membrane of a cell
The formation of a membrane domain
The tethering of proteins in the membrane to proteins in
the cytoskeleton
The import of glucose into intestinal cells - ANSWER-
Membrane proteins from showing lateral movement
through the entire plasma membrane of a cell
The voltage difference across a membrane is called:
Depolarization
The threshold potential
An action potential
The membrane potential - ANSWER-The membrane
potential
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What is the difference between channels and
transporters?
Only transporters are selective in which solutes they
transport
Transporters are much faster at moving solutes than
channels
All transporters require ATP hydrolysis, while channels
perform passive diffusion
Transporters move very small solutes, while channels
move larger molecules
Only transporters specifically bind to their solutes in a
similar manner as an enzyme binds its substrate -
ANSWER-Only transporters specifically bind to their
solutes in a similar manner as an enzyme binds its
substrate
If the sodium potassium pump stopped function in the
intestinal cells, which of the following would occur?
The sodium gradient would reach an equilibrium with the
intestinal lumen
the sodium inside the cell would decrease in concentration
glucose symport from the intestinal lumen would stop
the high glucose gradient in the cell would decrease -
ANSWER-The sodium gradient would reach an
equilibrium with the intestinal lumen
,3|Page
glucose symport from the intestinal lumen would stop
the high glucose gradient in the cell would decrease
Ion channels have different gating mechanisms. Which of
the following is NOT an example of how these
mechanisms work?
voltage gated ion channels open in response to a change
in water distribution across the membrane
a mechanically gated potassium channel opens in
response to physical stimulus
ligand gated ion channels require the binding of a
molecule that causes a conformation shift in the channel
protein
voltage gated ion channels can be affected by the
concentration gradients of positive or negatively charged
ions - ANSWER-voltage gated ion channels open in
response to a change in water distribution across the
membrane
During an action potential, which of the following actions
DOES NOT help return a depolarized membrane to its
resting membrane potential?
(*when I ask a "does not" question, first make a list of all
the things that DO help return a depolarized membrane to
its resting membrane potential)
, 4|Page
The flow of K+ OUT of the cell
The inactivation of voltage-gated Na+ channels
The opening of voltage-gated K+ channels
The opening of voltage-gated Na+ channels - ANSWER-
The opening of voltage-gated Na+ channels
Following excitation in a nerve membrane, the region goes
through a brief period during which it cannot be stimulated
again. What takes place during this period?
the membrane potential remains unchanged
ligands bind to voltage-gated Ca2+ channels
voltage-gated Na+ channels in the nerve cell membrane
are inactivated
ligand-gated Na+ channels in the nerve cell membrane are
inactivated - ANSWER-voltage-gated Na+ channels in the
nerve cell membrane are inactivated
The propagation of an action potential is due to many
sodium ions diffusing through the cytosol of the nerve
axon to the axon terminal.
True
False - ANSWER-false
Biol 320 Exam 3 Newest 2025/ 2026 Actual Exam
Complete Questions And Correct Answers ||VERIFIED
EXAM||(Verified Answers) |Already Graded A+||
LATEST EXAM UPDATE!!
Tight junctions found between the cells in our intestines
PREVENT
Small, non-polar molecules from using simple diffusion to
cross the plasma membrane
Membrane proteins from showing lateral movement
through the entire plasma membrane of a cell
The formation of a membrane domain
The tethering of proteins in the membrane to proteins in
the cytoskeleton
The import of glucose into intestinal cells - ANSWER-
Membrane proteins from showing lateral movement
through the entire plasma membrane of a cell
The voltage difference across a membrane is called:
Depolarization
The threshold potential
An action potential
The membrane potential - ANSWER-The membrane
potential
,2|Page
What is the difference between channels and
transporters?
Only transporters are selective in which solutes they
transport
Transporters are much faster at moving solutes than
channels
All transporters require ATP hydrolysis, while channels
perform passive diffusion
Transporters move very small solutes, while channels
move larger molecules
Only transporters specifically bind to their solutes in a
similar manner as an enzyme binds its substrate -
ANSWER-Only transporters specifically bind to their
solutes in a similar manner as an enzyme binds its
substrate
If the sodium potassium pump stopped function in the
intestinal cells, which of the following would occur?
The sodium gradient would reach an equilibrium with the
intestinal lumen
the sodium inside the cell would decrease in concentration
glucose symport from the intestinal lumen would stop
the high glucose gradient in the cell would decrease -
ANSWER-The sodium gradient would reach an
equilibrium with the intestinal lumen
,3|Page
glucose symport from the intestinal lumen would stop
the high glucose gradient in the cell would decrease
Ion channels have different gating mechanisms. Which of
the following is NOT an example of how these
mechanisms work?
voltage gated ion channels open in response to a change
in water distribution across the membrane
a mechanically gated potassium channel opens in
response to physical stimulus
ligand gated ion channels require the binding of a
molecule that causes a conformation shift in the channel
protein
voltage gated ion channels can be affected by the
concentration gradients of positive or negatively charged
ions - ANSWER-voltage gated ion channels open in
response to a change in water distribution across the
membrane
During an action potential, which of the following actions
DOES NOT help return a depolarized membrane to its
resting membrane potential?
(*when I ask a "does not" question, first make a list of all
the things that DO help return a depolarized membrane to
its resting membrane potential)
, 4|Page
The flow of K+ OUT of the cell
The inactivation of voltage-gated Na+ channels
The opening of voltage-gated K+ channels
The opening of voltage-gated Na+ channels - ANSWER-
The opening of voltage-gated Na+ channels
Following excitation in a nerve membrane, the region goes
through a brief period during which it cannot be stimulated
again. What takes place during this period?
the membrane potential remains unchanged
ligands bind to voltage-gated Ca2+ channels
voltage-gated Na+ channels in the nerve cell membrane
are inactivated
ligand-gated Na+ channels in the nerve cell membrane are
inactivated - ANSWER-voltage-gated Na+ channels in the
nerve cell membrane are inactivated
The propagation of an action potential is due to many
sodium ions diffusing through the cytosol of the nerve
axon to the axon terminal.
True
False - ANSWER-false
