Question 1

Describe an experiment to demonstrate that lipid composition and structure affect plasma membrane fluidity and stability.

Accepted Answer

To demonstrate the effect of lipid compo

Question 2

Two chambers containing aqueous solutions are separated by a membrane. Chamber 1 contains 10 mM Na+ while chamber 2 contains 1 mM Na+. The membrane potential (1 relative to 2) in this scenario

Accepted Answer

A)  is greater than 0 mV. 
B)  is equal to 0 mV. 
C)  is less than 0 mV. 
D)  cannot be determined based on the information given. 
A)  is greater than 0 mV. 
B)  is equal to 0 mV. 
C)  is less than 0 mV. 
D)  cannot be determined based on the information given.

Question 3

Osmosis is the movement of water

Accepted Answer

A)  using a carrier-mediated transport mechanism. 
B)  down a solute's concentration gradient. 
C)  down its own concentration gradient. 
D)  across a membrane irrespective of concentration gradients. 
E)  across a membrane down its own concentration gradient. 
A)  using a carrier-mediated transport mechanism. 
B)  down a solute's concentration gradient. 
C)  down its own concentration gradient. 
D)  across a membrane irrespective of concentration gradients. 
E)  across a membrane down its own concentration gradient.

Question 4

For most cells, the membrane potential is closer to the Ek+ (-90 mV) than for ENa+ (+ 60 mV). This is because

Accepted Answer

A)  EK+ Na+, and systems tend toward lower energy states. 
B)  cells like potassium better than sodium, so they work to maintain potassium closer to its equilibrium distribution. 
C)  cell membranes are equally permeable to Na+ and Cl-, so every time a Na+ comes in, its depolarizing effect is negated by a Cl- ion. 
D)  cell membranes are more permeable to K+ than Na+, so there are a greater number of pathways available for K+ to move towards its equilibrium distribution than are available for Na+ to do the same. 
E)  none of these. 
A)  EK+ Na+, and systems tend toward lower energy states. 
B)  cells like potassium better than sodium, so they work to maintain potassium closer to its equilibrium distribution. 
C)  cell membranes are equally permeable to Na+ and Cl-, so every time a Na+ comes in, its depolarizing effect is negated by a Cl- ion. 
D)  cell membranes are more permeable to K+ than Na+, so there are a greater number of pathways available for K+ to move towards its equilibrium distribution than are available for Na+ to do the same. 
E)  none of these.

Question 5

Match each sentence with the most appropriate choice:
-Exocytosis

Accepted Answer

A)  Potocytosis 
B)  secretion 
C)  ATP 
D)  PIP3 
E)  cAMP
F) DAG
G) Ca2+
H) equilibrium potential
I) cell volume
J) receptor 
A)  Potocytosis 
B)  secretion 
C)  ATP 
D)  PIP3 
E)  cAMP
F) DAG
G) Ca2+
H) equilibrium potential
I) cell volume
J) receptor

Question 6

Net diffusion leads to the establishment of an equilibrium, but not a steady state.

Accepted Answer

A) True 
 B)False

Question 7

Match each sentence with the most appropriate choice:
-PDE

Accepted Answer

A)  Potocytosis 
B)  secretion 
C)  ATP 
D)  PIP6 
E)  cAMP
F) DAG
G) Ca2+
H) equilibrium potential
I) cell volume
J) receptor 
A)  Potocytosis 
B)  secretion 
C)  ATP 
D)  PIP6 
E)  cAMP
F) DAG
G) Ca2+
H) equilibrium potential
I) cell volume
J) receptor

Question 8

Which of the following pairs have NO relationship?

Accepted Answer

A)  hydrostatic pressure and osmosis. 
B)  osmotic pressure and osmosis. 
C)  osmotic pressure and colligative properties of solutes. 
D)  all of these pairs have a relationship. 
E)  none of these pairs has a relationship. 
A)  hydrostatic pressure and osmosis. 
B)  osmotic pressure and osmosis. 
C)  osmotic pressure and colligative properties of solutes. 
D)  all of these pairs have a relationship. 
E)  none of these pairs has a relationship.

Question 9

Which of the following statements regarding the fatty acid tails of phospholipids is FALSE?

Accepted Answer

A)  Phospholipids with unsaturated tails make the bilayer more fluid because the tails contain fewer hydrogens and thus form fewer hydrogen bonds with each other. 
B)  Saturated phospholipids' tails pack more tightly against each other than do unsaturated tails. 
C)  Most membrane phospholipids have one fully saturated tail. 
D)  Phospholipid tails in a membrane can interact with each other via van der Waals interactions. 
E)  Fatty acid tails vary in length. 
A)  Phospholipids with unsaturated tails make the bilayer more fluid because the tails contain fewer hydrogens and thus form fewer hydrogen bonds with each other. 
B)  Saturated phospholipids' tails pack more tightly against each other than do unsaturated tails. 
C)  Most membrane phospholipids have one fully saturated tail. 
D)  Phospholipid tails in a membrane can interact with each other via van der Waals interactions. 
E)  Fatty acid tails vary in length.

Question 10

Nursing babies obtain some immunity by intestinal absorption of antibodies found in their mother's milk. This process requires the movement of intact antibodies from the lumen of the intestine into the blood. This process involves a combination of

Accepted Answer

A)  endocytosis. 
B)  exocytosis. 
C)  cotransport carriers. 
D)  endocytosis and cotransport carriers. 
E)  endocytosis and exocytosis. 
A)  endocytosis. 
B)  exocytosis. 
C)  cotransport carriers. 
D)  endocytosis and cotransport carriers. 
E)  endocytosis and exocytosis.

Question 11

Two chambers are separated by a cation-permeable membrane. The first chamber contains 10 mM NaCl and 1 mM KCl, and the second chamber contains 10 mM KCl and 1 mM NaCl. At equilibrium, the membrane potential (with chamber 1 relative to chamber 2) is

Accepted Answer

A)  greater than 0 mV. 
B)  equal to 0 mV. 
C)  less than 0 mV. 
D)  unable to be determined without knowing the temperature. 
A)  greater than 0 mV. 
B)  equal to 0 mV. 
C)  less than 0 mV. 
D)  unable to be determined without knowing the temperature.

Question 12

Signaling molecules are divided into categories based upon their chemical structure. Which of the following is NOT a chemical structure category for signaling molecules?

Accepted Answer

A)  retinoids 
B)  gases 
C)  pyrimidines 
D)  amines 
E)  peptides 
A)  retinoids 
B)  gases 
C)  pyrimidines 
D)  amines 
E)  peptides

Question 13

Explain why a large increase in extracellular potassium is more life-threatening than a
 similar increase in extracellular sodium.

Accepted Answer

A large increase in extracellular potass

Question 14

The term potocytosis refers to

Accepted Answer

A)  the uptake of substances through the activity of caveolae. 
B)  the specific uptake of tetrahydrocannabinol by facilitated diffusion. 
C)  the uptake of solid substances involving the formation of pseudopods. 
D)  the uptake of liquids through cellular drinking. 
A)  the uptake of substances through the activity of caveolae. 
B)  the specific uptake of tetrahydrocannabinol by facilitated diffusion. 
C)  the uptake of solid substances involving the formation of pseudopods. 
D)  the uptake of liquids through cellular drinking.

Question 15

A solution that is hypertonic is also hyperosmotic.

Accepted Answer

A) True 
 B)False

Question 16

Nanotubes are one example of intercellular communication in mammals.

Accepted Answer

A) True 
 B)False

Question 17

Match each sentence with the most appropriate choice:
-Agonist

Accepted Answer

A)  Potocytosis 
B)  secretion 
C)  ATP 
D)  PIP11 
E)  cAMP
F) DAG
G) Ca2+
H) equilibrium potential
I) cell volume
J) receptor 
A)  Potocytosis 
B)  secretion 
C)  ATP 
D)  PIP11 
E)  cAMP
F) DAG
G) Ca2+
H) equilibrium potential
I) cell volume
J) receptor

Question 18

Which of the following would disqualify a chemical messenger from being considered a paracrine signal?

Accepted Answer

A)  It is an organic molecule. 
B)  It is not transported in the blood. 
C)  It affects the cell that released it. 
D)  Once released, it is distributed to its target(s) by simple diffusion. 
E)  It is released as a specific response to a signal. 
A)  It is an organic molecule. 
B)  It is not transported in the blood. 
C)  It affects the cell that released it. 
D)  Once released, it is distributed to its target(s) by simple diffusion. 
E)  It is released as a specific response to a signal.

Question 19

A scientist measuring the rate of uptake of radiolabeled alanine by cultured cells finds that rates are faster when the experiments are carried out in a buffered, balanced salts solution than when the experiments are carried out in a complete (containing all nutrients required for survival and growth) medium. The most likely explanation for this observation is

Accepted Answer

A)  the concentration gradient for alanine is steeper in the former case than the latter. 
B)  the crenation (shrinkage of cells) in the salts solution increases the surface area-to-volume ratio for the cells increasing the rate of diffusion. 
C)  the absence of amino acids in the balanced salts solution decreases the abundance of molecules competing for transport, and therefore increases the apparent transport rate. 
D)  the temperature of the balanced salt solution is higher, so rates of transport are greater. 
E)  no response provides a valid answer. 
A)  the concentration gradient for alanine is steeper in the former case than the latter. 
B)  the crenation (shrinkage of cells) in the salts solution increases the surface area-to-volume ratio for the cells increasing the rate of diffusion. 
C)  the absence of amino acids in the balanced salts solution decreases the abundance of molecules competing for transport, and therefore increases the apparent transport rate. 
D)  the temperature of the balanced salt solution is higher, so rates of transport are greater. 
E)  no response provides a valid answer.

Question 20

In a lab experiment with isolated lung cells you observe a linear uptake in choline from the extracellular medium by the cells until the extracellular concentration of choline reaches 200 nM. At this concentration the curve levels off and the same rate of uptake is seen at 200 and 225 nM extracellular choline. What has happened that can explain this observation?

Accepted Answer

A)  Cellular and extracellular choline concentrations are at equilibrium. 
B)  The transporters for choline saturate at 200 nM. 
C)  At choline concentrations of 200 nM and above, the osmotic pressure of the cytoplasm prevents additional choline from entering the cell. 
D)  The cell cannot synthesis enough ATP to keep up with the energy demand of the carrier. 
E)  None of these. 
A)  Cellular and extracellular choline concentrations are at equilibrium. 
B)  The transporters for choline saturate at 200 nM. 
C)  At choline concentrations of 200 nM and above, the osmotic pressure of the cytoplasm prevents additional choline from entering the cell. 
D)  The cell cannot synthesis enough ATP to keep up with the energy demand of the carrier. 
E)  None of these.

Describe an experiment to demonstrate that lipid composition and structure affect plasma membrane fluidity and stability.

Two chambers containing aqueous solutions are separated by a membrane. Chamber 1 contains 10 mM Na⁺ while chamber 2 contains 1 mM Na⁺. The membrane potential (1 relative to 2) in this scenario

Osmosis is the movement of water

For most cells, the membrane potential is closer to the E_k+ (-90 mV) than for E_Na+ (+ 60 mV). This is because

Match each sentence with the most appropriate choice: -Exocytosis

Net diffusion leads to the establishment of an equilibrium, but not a steady state.

Match each sentence with the most appropriate choice: -PDE

Which of the following pairs have NO relationship?

Which of the following statements regarding the fatty acid tails of phospholipids is FALSE?

Nursing babies obtain some immunity by intestinal absorption of antibodies found in their mother's milk. This process requires the movement of intact antibodies from the lumen of the intestine into the blood. This process involves a combination of

Two chambers are separated by a cation-permeable membrane. The first chamber contains 10 mM NaCl and 1 mM KCl, and the second chamber contains 10 mM KCl and 1 mM NaCl. At equilibrium, the membrane potential (with chamber 1 relative to chamber 2) is

Signaling molecules are divided into categories based upon their chemical structure. Which of the following is NOT a chemical structure category for signaling molecules?

Explain why a large increase in extracellular potassium is more life-threatening than a similar increase in extracellular sodium.

The term potocytosis refers to

A solution that is hypertonic is also hyperosmotic.

Nanotubes are one example of intercellular communication in mammals.

Match each sentence with the most appropriate choice: -Agonist

Which of the following would disqualify a chemical messenger from being considered a paracrine signal?

Homeostasis and Integration: The Foundations of Physiology

Cellular and Molecular Physiology

Neuronal Physiology

Nervous Systems

Sensory Physiology

Endocrine Systems

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Defense Systems

Respiratory Systems

Excretory Systems

Fluid and Acid-Base Balance

Digestive Systems

Energy Balance and Thermal Physiology

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Exam 3: Membrane Physiology

Describe an experiment to demonstrate that lipid composition and structure affect plasma membrane fluidity and stability.

Two chambers containing aqueous solutions are separated by a membrane. Chamber 1 contains 10 mM Na+ while chamber 2 contains 1 mM Na+. The membrane potential (1 relative to 2) in this scenario

Osmosis is the movement of water

For most cells, the membrane potential is closer to the Ek+ (-90 mV) than for ENa+ (+ 60 mV). This is because

Match each sentence with the most appropriate choice: -Exocytosis

Net diffusion leads to the establishment of an equilibrium, but not a steady state.

Match each sentence with the most appropriate choice: -PDE

Which of the following pairs have NO relationship?

Which of the following statements regarding the fatty acid tails of phospholipids is FALSE?

Nursing babies obtain some immunity by intestinal absorption of antibodies found in their mother's milk. This process requires the movement of intact antibodies from the lumen of the intestine into the blood. This process involves a combination of

Two chambers are separated by a cation-permeable membrane. The first chamber contains 10 mM NaCl and 1 mM KCl, and the second chamber contains 10 mM KCl and 1 mM NaCl. At equilibrium, the membrane potential (with chamber 1 relative to chamber 2) is

Signaling molecules are divided into categories based upon their chemical structure. Which of the following is NOT a chemical structure category for signaling molecules?

Explain why a large increase in extracellular potassium is more life-threatening than a similar increase in extracellular sodium.

The term potocytosis refers to

A solution that is hypertonic is also hyperosmotic.

Nanotubes are one example of intercellular communication in mammals.

Match each sentence with the most appropriate choice: -Agonist

Which of the following would disqualify a chemical messenger from being considered a paracrine signal?

Homeostasis and Integration: The Foundations of Physiology

Cellular and Molecular Physiology

Neuronal Physiology

Nervous Systems

Sensory Physiology

Endocrine Systems

Muscle Physiology

Circulatory Systems

Defense Systems

Respiratory Systems

Excretory Systems

Fluid and Acid-Base Balance

Digestive Systems

Energy Balance and Thermal Physiology

Reproductive Systems

Filters

Two chambers containing aqueous solutions are separated by a membrane. Chamber 1 contains 10 mM Na⁺ while chamber 2 contains 1 mM Na⁺. The membrane potential (1 relative to 2) in this scenario

For most cells, the membrane potential is closer to the E_k+ (-90 mV) than for E_Na+ (+ 60 mV). This is because