Question 1

Match each sentence with the most appropriate choice:
-PKC

Accepted Answer

A)  Potocytosis 
B)  secretion 
C)  ATP 
D)  PIP7 
E)  cAMP
F) DAG
G) Ca2+
H) equilibrium potential
I) cell volume
J) receptor

Question 2

The G-protein signaling pathway begins with the binding of the first messenger to
 adenylyl cyclase.

Accepted Answer

A) True 
 B)False

Question 3

Which of the following does NOT directly affect the rate of diffusion of a substance across a membrane?

Accepted Answer

A)  concentration gradient 
B)  cellular volume 
C)  permeability of the membrane to the diffusing substance 
D)  surface area across which diffusion is taking place 
E)  molecular weight of the diffusing substance

Question 4

Molecules that can cross a membrane unassisted due so either by

Accepted Answer

A)  carrier mediated transport or facilitated diffusion. 
B)  passive diffusion or active transport. 
C)  conduction or passive transport. 
D)  facilitated diffusion or active transport. 
E)  none of these.

Question 5

Which of the following statements regarding lipid membranes is true?

Accepted Answer

A)  Phospholipids will spontaneously form liposomes in nonpolar solvents. 
B)  A solution of pure fatty acids forms a lipid bilayer in a polar solvent. 
C)  Membrane lipids move laterally within their own layer. 
D)  Membrane lipids frequently move between one layer of the bilayer and the other. 
E)  The preferred form of a lipid bilayer in water is a flat sheet with exposed edges.

Question 6

Ion channels

Accepted Answer

A)  can exist in open or closed states. 
B)  are typically selective with respect to the types of substances that pass through them. 
C)  can selectively repel particular ions. 
D)  all of these. 
E)  none of these.

Question 7

Cell membranes have a ____ structure with the polar head groups of the phospholipids facing toward the aqueous environment and the ____ facing toward the interior of the membrane.

Accepted Answer

A)  bilayer, hydrophilic tails 
B)  bilayer, hydrophobic tails 
C)  micellar, hydrophilic tails 
D)  liposomal, hydrophilic tails 
E)  liposomal, hydrophobic tails

Question 8

Cholesterol is a membrane lipid that

Accepted Answer

A)  reduces the permeability of gill membranes to water. 
B)  affects the activity of membrane proteins. 
C)  regulates membrane fluidity and stability. 
D)  two of these. 
E)  all of these.

Question 9

Which of the following sequences best represents the order of events in the cAMP second messenger pathway?

Accepted Answer

A)  cAMP$\rightarrow$receptor $\rightarrow$ G-protein activation $\rightarrow$PKA $\rightarrow$ phosphoproteins 
B)  receptor $\rightarrow$ G-protein activation $\rightarrow$ AC $\rightarrow$ cAMP $\rightarrow$ PKA $\rightarrow$ phosphoproteins 
C)  AC $\rightarrow$ decreased temperature $\rightarrow$ phospholipid-breakdown $\rightarrow$ cAMP $\rightarrow$ PKA $\rightarrow$phosphoproteins 
D)  G-protein activation $\rightarrow$ GDP $\rightarrow$ cGMP $\rightarrow$ cAMP $\rightarrow$ PKA $\rightarrow$phosphoproteins 
E)  None of the above.

Question 10

Which of the following is a NOT direct function of the Na+-K+ pump?

Accepted Answer

A)  development of a Na+ gradient across the cell membrane 
B)  development of a K+ gradient across the cell membrane 
C)  regulation of cellular pH 
D)  cell volume regulation 
E)  all of these are direct functions of this pump.

Question 11

Membrane proteins are found

Accepted Answer

A)  as distinct layers with one layer facing the extracellular fluid and the other facing the intracellular fluid. 
B)  both embedded in and associated with the lipid bilayer of the plasma membrane. 
C)  associated with the lipid bilayer of the plasma membrane, but not actually embedded in it. 
D)  only in the plasma membrane, and not in other cellular membranes. 
E)  none of these.

Question 12

Neurosecretory neurons are adapted for hormone production and therefore do not
 conduct.

Accepted Answer

A) True 
 B)False

Question 13

The internal (intracellular) receptor for steroid hormones acts as a transcription factor. Therefore, the cellular response to a steroid would be expected to include

Accepted Answer

A)  an increase in mRNA produced from specific genes. 
B)  an increase in protein production, representing specific gene products. 
C)  both of these. 
D)  neither of these.

Question 14

The lipid bilayer is held together mainly by

Accepted Answer

A)  covalent bonding between membrane lipids. 
B)  hydrogen-bonding between the phospholipids' tails. 
C)  repulsion between the phospholipids' tails and water. 
D)  covalent bonding between the ends of phospholipids tails in opposite layers. 
E)  hydrogen-bonding between the head groups of the phospholipids.

Question 15

Assuming that the Na⁺-K⁺ pumps are located on the basolateral membrane (the side away from the environment) of salmon gill epithelium, explain how increasing the number of pumps helps the animal adjust to life in the sea.

Accepted Answer

The answer of Assuming that the Na⁺-K⁺ pumps are located...

Question 16

Match each sentence with the most appropriate choice:
-PLC

Accepted Answer

A)  Potocytosis 
B)  secretion 
C)  ATP 
D)  PIP5 
E)  cAMP
F) DAG
G) Ca2+
H) equilibrium potential
I) cell volume
J) receptor

Question 17

The affect a chemical messenger elicits in a cell is determined primarily by the identity of

Accepted Answer

A)  the chemical messenger. 
B)  the receptor for the chemical messenger. 
C)  the second messengers present in the cell. 
D)  the cell. 
E)  the organism.

Question 18

All cells (not just animal cells) have

Accepted Answer

A)  mitochondria. 
B)  a cell membrane. 
C)  a cell wall. 
D)  a nucleus. 
E)  microtubules.

Question 19

The electrochemical gradient is the charge difference that occurs across the plasma
 membrane.

Accepted Answer

A) True 
 B)False

Question 20

Osmotic pressure is

Accepted Answer

A)  a measure of the concentration of solvent in a solution. 
B)  equal to the hydrostatic pressure required to oppose the movement of water into a solution. 
C)  low in a solution with a high solute concentration. 
D)  dependent upon the lipid composition of the membrane. 
E)  two of these are correct.

Exam 3: Membrane Physiology

Match each sentence with the most appropriate choice: -PKC

The G-protein signaling pathway begins with the binding of the first messenger to adenylyl cyclase.

Which of the following does NOT directly affect the rate of diffusion of a substance across a membrane?

Molecules that can cross a membrane unassisted due so either by

Which of the following statements regarding lipid membranes is true?

Ion channels

Cell membranes have a structure with the polar head groups of the phospholipids facing toward the aqueous environment and the facing toward the interior of the membrane.

Cholesterol is a membrane lipid that

Which of the following sequences best represents the order of events in the cAMP second messenger pathway?

Which of the following is a NOT direct function of the Na⁺-K⁺ pump?

Membrane proteins are found

Neurosecretory neurons are adapted for hormone production and therefore do not conduct.

The internal (intracellular) receptor for steroid hormones acts as a transcription factor. Therefore, the cellular response to a steroid would be expected to include

The lipid bilayer is held together mainly by

Assuming that the Na⁺-K⁺ pumps are located on the basolateral membrane (the side away from the environment) of salmon gill epithelium, explain how increasing the number of pumps helps the animal adjust to life in the sea.

Match each sentence with the most appropriate choice: -PLC

The affect a chemical messenger elicits in a cell is determined primarily by the identity of

All cells (not just animal cells) have

The electrochemical gradient is the charge difference that occurs across the plasma membrane.

Osmotic pressure is

Exam 3: Membrane Physiology

Match each sentence with the most appropriate choice: -PKC

The G-protein signaling pathway begins with the binding of the first messenger to adenylyl cyclase.

Which of the following does NOT directly affect the rate of diffusion of a substance across a membrane?

Molecules that can cross a membrane unassisted due so either by

Which of the following statements regarding lipid membranes is true?

Ion channels

Cell membranes have a ____ structure with the polar head groups of the phospholipids facing toward the aqueous environment and the ____ facing toward the interior of the membrane.

Cholesterol is a membrane lipid that

Which of the following sequences best represents the order of events in the cAMP second messenger pathway?

Which of the following is a NOT direct function of the Na+-K+ pump?

Membrane proteins are found

Neurosecretory neurons are adapted for hormone production and therefore do not conduct.

The internal (intracellular) receptor for steroid hormones acts as a transcription factor. Therefore, the cellular response to a steroid would be expected to include

The lipid bilayer is held together mainly by

Assuming that the Na+-K+ pumps are located on the basolateral membrane (the side away from the environment) of salmon gill epithelium, explain how increasing the number of pumps helps the animal adjust to life in the sea.

Match each sentence with the most appropriate choice: -PLC

The affect a chemical messenger elicits in a cell is determined primarily by the identity of

All cells (not just animal cells) have

The electrochemical gradient is the charge difference that occurs across the plasma membrane.

Osmotic pressure is

Cell membranes have a structure with the polar head groups of the phospholipids facing toward the aqueous environment and the facing toward the interior of the membrane.

Which of the following is a NOT direct function of the Na⁺-K⁺ pump?

Assuming that the Na⁺-K⁺ pumps are located on the basolateral membrane (the side away from the environment) of salmon gill epithelium, explain how increasing the number of pumps helps the animal adjust to life in the sea.