Bio 344 NAU FINAL EXAM
QUESTIONS AND 100% CORRECT
ANSWERS (2025-2026) EDITION.
Why can a sodium ion not pass through a potassium leak channel? - Answer The sodium ion
cannot interact correctly with the oxygen atoms of the selectivity filter of the potassium leak
channel.
What is a difference between active transport and passive transport? - Answer Passive
transport goes from high concentration to low concentration while active transport goes from
low concentration to high concentration
What is a property of the membrane spanning region of a membrane protein? - Answer It
contains amino acids with non-polar side chains.
In order to maintain osmotic balance and maintain cell volume, what would the Na+/K+ pump
do if the cell is exposed to pure water? - Answer Start pumping faster because 3 ions are
pumped out for two that come in and the cell needs to get rid of as many ions as possible.
How many Na+ ions does the Na+/K+ pump transport during each cycle? - Answer 3
What kind of ATP driven pump is the Na+/K+ pump? - Answer P-type pump
What Molecule is Polar - Answer H2O
What process below will be facilitated by active transport? - Answer Movement of glucose
into an intestinal epithelial cell.
What happens to the membrane potential when a potassium leak channel opens up during an
action potential? - Answer The membrane potential will be restored with a negative charge on
the cytosolic layer of the membrane.
What energy source is used to transport glucose from inside an intestinal epithelial cell to the
outside? - Answer glucose is exported passively from intestinal epithelial cells and therefore
no energy source is required.
, What is the anion transporter in red blood cells used for? - Answer It removes CO2 from the
body in the form of HCO3-.
What would a large positive peak on a hydropathy plot signify? - Answer That the protein is
likely to have a membrane spanning region
What does the influx of Ca2+ into an axon terminal cause? - Answer It causes synaptic vesicles
to fuse with the membrane.
Most membrane proteins in a human red blood cell are... - Answer Associated with the
cytoskeleton
Why does an action potential not move backwards towards the dendrites of a nerve cell? -
Answer Because the membrane potential is restored when an ion channel is inactivated so
that after inactivation the channel remains closed
Where does the energy to transport glucose into a cell against the glucose concentration
gradient come from? - Answer Na+ gradient
How is a lipid raft different from the rest of the membrane? - Answer It is enriched in
sphingomyelin.
What is a characteristic of axon terminals on a nerve cell? - Answer They contain vescicles with
neurotransmitters
How are ion channels, that are the first to open, gated in muscle cells at the neuromuscular
junction? - Answer by neurotransmitters
What causes the kink in one of the phospholipids fatty acid tails? - Answer a cis double bond.
What is Sodium Dodecyl Sulfate? - Answer a detergent
If K+ ions rush out of a cell what will happen to the electrochemical gradient of Na+ in an animal
cell? - Answer The electrochemical gradient will increase promoting transport of Na+ across
the membrane.
QUESTIONS AND 100% CORRECT
ANSWERS (2025-2026) EDITION.
Why can a sodium ion not pass through a potassium leak channel? - Answer The sodium ion
cannot interact correctly with the oxygen atoms of the selectivity filter of the potassium leak
channel.
What is a difference between active transport and passive transport? - Answer Passive
transport goes from high concentration to low concentration while active transport goes from
low concentration to high concentration
What is a property of the membrane spanning region of a membrane protein? - Answer It
contains amino acids with non-polar side chains.
In order to maintain osmotic balance and maintain cell volume, what would the Na+/K+ pump
do if the cell is exposed to pure water? - Answer Start pumping faster because 3 ions are
pumped out for two that come in and the cell needs to get rid of as many ions as possible.
How many Na+ ions does the Na+/K+ pump transport during each cycle? - Answer 3
What kind of ATP driven pump is the Na+/K+ pump? - Answer P-type pump
What Molecule is Polar - Answer H2O
What process below will be facilitated by active transport? - Answer Movement of glucose
into an intestinal epithelial cell.
What happens to the membrane potential when a potassium leak channel opens up during an
action potential? - Answer The membrane potential will be restored with a negative charge on
the cytosolic layer of the membrane.
What energy source is used to transport glucose from inside an intestinal epithelial cell to the
outside? - Answer glucose is exported passively from intestinal epithelial cells and therefore
no energy source is required.
, What is the anion transporter in red blood cells used for? - Answer It removes CO2 from the
body in the form of HCO3-.
What would a large positive peak on a hydropathy plot signify? - Answer That the protein is
likely to have a membrane spanning region
What does the influx of Ca2+ into an axon terminal cause? - Answer It causes synaptic vesicles
to fuse with the membrane.
Most membrane proteins in a human red blood cell are... - Answer Associated with the
cytoskeleton
Why does an action potential not move backwards towards the dendrites of a nerve cell? -
Answer Because the membrane potential is restored when an ion channel is inactivated so
that after inactivation the channel remains closed
Where does the energy to transport glucose into a cell against the glucose concentration
gradient come from? - Answer Na+ gradient
How is a lipid raft different from the rest of the membrane? - Answer It is enriched in
sphingomyelin.
What is a characteristic of axon terminals on a nerve cell? - Answer They contain vescicles with
neurotransmitters
How are ion channels, that are the first to open, gated in muscle cells at the neuromuscular
junction? - Answer by neurotransmitters
What causes the kink in one of the phospholipids fatty acid tails? - Answer a cis double bond.
What is Sodium Dodecyl Sulfate? - Answer a detergent
If K+ ions rush out of a cell what will happen to the electrochemical gradient of Na+ in an animal
cell? - Answer The electrochemical gradient will increase promoting transport of Na+ across
the membrane.
