BIOL 212 Exam 1 & 2 Questions and
Verified Answers
GIVEN: The red blood cell membrane is impermeable to mannitol, but is permeable to both
water and glucose. Red blood cells will shrink the most when immersed in: - CORRECT
ANSWERS -a hyperosmotic mannitol solution
During hemoglobin metabolism, the breakdown products of heme become part of: - CORRECT
ANSWERS -bile
If potassium were at equilibrium across the cell membrane, then what would be the direction
of the electrochemical driving force acting on potassium? - CORRECT ANSWERS -there is no
electrochemical force at equilibrium
Mice from a certain lab strain remain healthy as long as you feed them regularly and do not let
them exercise. After they eat, their blood glucose level rises slightly and then declines to a
homeostatic level. However, if these mice fast or exercise at all, their blood glucose drops
dangerously. Which hypothesis best explains their problem? - CORRECT ANSWERS -The mice
lack glucagon receptors on their cells.
Anesthetics cross the cell membranes in nerve tissue relatively easily. Therefore, anesthetics
have a: - CORRECT ANSWERS -high partition coefficient
A scientist is studying the passive movement of chemicals into a cell. He measures the rate at
which two chemicals diffuse into a cell, as a function of their external concentration. Chemical
A's diffusion is directly proportional to the extracellular concentration but eventually reaches a
transport maximum, while Chemical B's rate of transport continues to be directly proportional
to external concentration.
How can one explain the differences in these diffusion rates? - CORRECT ANSWERS -Chemical A
is moving by facilitated diffusion, while Chemical B is diffusing through the phospholipids or
through a channel.
Given that oubain blocks the Na+/K+ pump, how would this drug affect glucose transport in the
small intestine? - CORRECT ANSWERS -Compared to normal, less glucose would be absorbed
from the lumen of the small intestine.
You have a 0.022 OsM solution of glucose. This solution is: - CORRECT ANSWERS -hypo-osmotic
to human cells.
One long-term consequence of diabetes mellitus is that the basement membrane below the
endothelial cells of capillary walls becomes thicker. If this happens, according to Fick's Law, the
, rate of diffusion of substances from the blood to the tissues will: - CORRECT ANSWERS -
decrease
The primary cation inside the cell is: - CORRECT ANSWERS -potassium
Under low oxygen conditions, __________ must unload its electrons to allow glycolysis to
continue its production of ATP: - CORRECT ANSWERS -NADH
A 10% starch solution is separated from pure water by a membrane which is impermeable to
starch. What will happen? - CORRECT ANSWERS -Net water movement will eventually stop as a
result of an opposing hydrostatic pressure.
The end products of the Krebs cycle include all of the following except: - CORRECT ANSWERS -
pyruvate
If the concentration of bicarbonate ions (HCO3-) in the ICF is 10 mM and the concentration in
the ECF is 28 mM, what would be the equilibrium potential for bicarbonate? - CORRECT
ANSWERS --27 mV
The GLUT family of molecules are: - CORRECT ANSWERS -carrier proteins for the facilitated
diffusion of glucose
Which is a TRUE statement about the resting membrane potential in a typical neuron? -
CORRECT ANSWERS -The sodium-potassium pump maintains the sodium and potassium
concentration gradients; having these concentration gradients is critical to maintaining a steady
resting membrane potential.
Given: the atomic mass of calcium is 40.1 g/mole, and the atomic mass of chloride is 35.5
g/mole. What % solution is a 3.0 OsM CaCl2 solution? - CORRECT ANSWERS -11.1%
A molecule that is similar in structure to a ligand, binds to the normal ligand's receptor on a
target cell, and produces a similar biological response in the cell is called a(n): - CORRECT
ANSWERS -agonist
The sodium ion (Na+) becomes more hydrated than the potassium ion (K+) because: - CORRECT
ANSWERS -the sodium ion has a greater density of surface charge
Midway through a 5-mile workout a runner begins to sweat profusely. In the feedback loop for
temperature regulation, the sweat glands producing the sweat would be considered the: -
CORRECT ANSWERS -effector
The substance HES (hydroxyethyl starch) is a plasma volume expander. In the year 2000, the
International Ski Federation listed HES as a banned substance for international competition.
What is the likely explanation for why a skier in the Olympics might use a plasma expander? -
CORRECT ANSWERS -If a skier had an abnormally high hematocrit due to blood doping, the
hematocrit could be reduced by taking a plasma volume expander.
Verified Answers
GIVEN: The red blood cell membrane is impermeable to mannitol, but is permeable to both
water and glucose. Red blood cells will shrink the most when immersed in: - CORRECT
ANSWERS -a hyperosmotic mannitol solution
During hemoglobin metabolism, the breakdown products of heme become part of: - CORRECT
ANSWERS -bile
If potassium were at equilibrium across the cell membrane, then what would be the direction
of the electrochemical driving force acting on potassium? - CORRECT ANSWERS -there is no
electrochemical force at equilibrium
Mice from a certain lab strain remain healthy as long as you feed them regularly and do not let
them exercise. After they eat, their blood glucose level rises slightly and then declines to a
homeostatic level. However, if these mice fast or exercise at all, their blood glucose drops
dangerously. Which hypothesis best explains their problem? - CORRECT ANSWERS -The mice
lack glucagon receptors on their cells.
Anesthetics cross the cell membranes in nerve tissue relatively easily. Therefore, anesthetics
have a: - CORRECT ANSWERS -high partition coefficient
A scientist is studying the passive movement of chemicals into a cell. He measures the rate at
which two chemicals diffuse into a cell, as a function of their external concentration. Chemical
A's diffusion is directly proportional to the extracellular concentration but eventually reaches a
transport maximum, while Chemical B's rate of transport continues to be directly proportional
to external concentration.
How can one explain the differences in these diffusion rates? - CORRECT ANSWERS -Chemical A
is moving by facilitated diffusion, while Chemical B is diffusing through the phospholipids or
through a channel.
Given that oubain blocks the Na+/K+ pump, how would this drug affect glucose transport in the
small intestine? - CORRECT ANSWERS -Compared to normal, less glucose would be absorbed
from the lumen of the small intestine.
You have a 0.022 OsM solution of glucose. This solution is: - CORRECT ANSWERS -hypo-osmotic
to human cells.
One long-term consequence of diabetes mellitus is that the basement membrane below the
endothelial cells of capillary walls becomes thicker. If this happens, according to Fick's Law, the
, rate of diffusion of substances from the blood to the tissues will: - CORRECT ANSWERS -
decrease
The primary cation inside the cell is: - CORRECT ANSWERS -potassium
Under low oxygen conditions, __________ must unload its electrons to allow glycolysis to
continue its production of ATP: - CORRECT ANSWERS -NADH
A 10% starch solution is separated from pure water by a membrane which is impermeable to
starch. What will happen? - CORRECT ANSWERS -Net water movement will eventually stop as a
result of an opposing hydrostatic pressure.
The end products of the Krebs cycle include all of the following except: - CORRECT ANSWERS -
pyruvate
If the concentration of bicarbonate ions (HCO3-) in the ICF is 10 mM and the concentration in
the ECF is 28 mM, what would be the equilibrium potential for bicarbonate? - CORRECT
ANSWERS --27 mV
The GLUT family of molecules are: - CORRECT ANSWERS -carrier proteins for the facilitated
diffusion of glucose
Which is a TRUE statement about the resting membrane potential in a typical neuron? -
CORRECT ANSWERS -The sodium-potassium pump maintains the sodium and potassium
concentration gradients; having these concentration gradients is critical to maintaining a steady
resting membrane potential.
Given: the atomic mass of calcium is 40.1 g/mole, and the atomic mass of chloride is 35.5
g/mole. What % solution is a 3.0 OsM CaCl2 solution? - CORRECT ANSWERS -11.1%
A molecule that is similar in structure to a ligand, binds to the normal ligand's receptor on a
target cell, and produces a similar biological response in the cell is called a(n): - CORRECT
ANSWERS -agonist
The sodium ion (Na+) becomes more hydrated than the potassium ion (K+) because: - CORRECT
ANSWERS -the sodium ion has a greater density of surface charge
Midway through a 5-mile workout a runner begins to sweat profusely. In the feedback loop for
temperature regulation, the sweat glands producing the sweat would be considered the: -
CORRECT ANSWERS -effector
The substance HES (hydroxyethyl starch) is a plasma volume expander. In the year 2000, the
International Ski Federation listed HES as a banned substance for international competition.
What is the likely explanation for why a skier in the Olympics might use a plasma expander? -
CORRECT ANSWERS -If a skier had an abnormally high hematocrit due to blood doping, the
hematocrit could be reduced by taking a plasma volume expander.
