Question 1

Matching

-With respect to polarity,membrane lipids can be described as ______.

Accepted Answer

A)  amphiphiles 
B)  vitamin D 
C)  arachidonic acid 
D)  phosphatidylethanolamine 
E)  sterol
F) gangliosides
G) phosphatidylcholine
H) glycerophospholipids
I) sphingomyelins
J) cholesterol
K) triacylglycerols
L) plasmalogen
M) nonpolar 
A)  amphiphiles 
B)  vitamin D 
C)  arachidonic acid 
D)  phosphatidylethanolamine 
E)  sterol
F) gangliosides
G) phosphatidylcholine
H) glycerophospholipids
I) sphingomyelins
J) cholesterol
K) triacylglycerols
L) plasmalogen
M) nonpolar

Question 2

Which of the following points to the correct location of attachment for a fatty acid which would yield a ceramide?

Accepted Answer

A) Location A 
B) Location B 
C) Location C 
D) Location B or C 
E) The correct location is not shown 
A) Location A 
B) Location B 
C) Location C 
D) Location B or C 
E) The correct location is not shown

Question 3

Coated vesicles are used to ensure that the enclosed protein maintains its proper orientation.Clathrin is one type of protein used to coat vesicles.Which of the following is true regarding clathrin vesicles?

Accepted Answer

A) They transport proteins between successive components of the Golgi compartments. 
B) They transport transmembrane proteins and GPI-linked proteins from the Golgi to the plasma membrane. 
C) They transport proteins from the ER to the Golgi. 
D) They form a rigid complex capable of protecting protein structure and orientation as it is passed from hydrophobic to hydrophilic environments. 
E) None of the above. 
A) They transport proteins between successive components of the Golgi compartments. 
B) They transport transmembrane proteins and GPI-linked proteins from the Golgi to the plasma membrane. 
C) They transport proteins from the ER to the Golgi. 
D) They form a rigid complex capable of protecting protein structure and orientation as it is passed from hydrophobic to hydrophilic environments. 
E) None of the above.

Question 4

Which of the following classes of proteins associates with the membrane bilayer with the lowest energy and would therefore be most difficult to separate from the membrane?

Accepted Answer

A) extrinsic proteins 
B) lipid-linked proteins 
C) transmembrane proteins 
D) peripheral proteins 
E) hydrophilic proteins 
A) extrinsic proteins 
B) lipid-linked proteins 
C) transmembrane proteins 
D) peripheral proteins 
E) hydrophilic proteins

Question 5

Which of the following lipid types is the least polar?

Accepted Answer

A) triacylglycerols 
B) glycerophospholipids 
C) sphingolipids 
D) gangliosides 
E) glycolipids 
A) triacylglycerols 
B) glycerophospholipids 
C) sphingolipids 
D) gangliosides 
E) glycolipids

Question 6

Which of the following proteins are synthesized on free ribosomes?

Accepted Answer

A) mitochondrial proteins 
B) secretory proteins 
C) signal peptides 
D) lysosomal proteins 
E) transmembrane proteins 
A) mitochondrial proteins 
B) secretory proteins 
C) signal peptides 
D) lysosomal proteins 
E) transmembrane proteins

Question 7

Sphingolipids
(I)contain a glycerol core with a phosphocholine headgroup.
(II)contain a modified sphingosine.
(III)often function as receptor components of membranes.
(IV)function as a precursor to sterols.

Accepted Answer

A) I,II,IV 
B) II,IV 
C) I,II,III 
D) II,III 
E) II,III,IV 
A) I,II,IV 
B) II,IV 
C) I,II,III 
D) II,III 
E) II,III,IV

Question 8

Lung surfactants function to decrease the likelihood of collapse of the alveoli when air is expired.Based on your knowledge of lipids and amphipathic molecules,which of the following explains the mechanism by which the dipalmitoyl phosphatidylcholine (DPPC)can accomplish this task?

Accepted Answer

A) The hydrophilic head groups are bulky and expand the surface area of the alveoli. 
B) The inclusion of saturated fatty acids on the glycerophospholipid allows close packing of tail groups which are fully extended and prevent collapse upon expiration. 
C) The hydrophobic portion of the DPPC repel air,forcing the alveoli space open. 
D) The choline portion of the molecule is bulky,thus increasing surface area of alveoli. 
E) None of the above explain the mechanism. 
A) The hydrophilic head groups are bulky and expand the surface area of the alveoli. 
B) The inclusion of saturated fatty acids on the glycerophospholipid allows close packing of tail groups which are fully extended and prevent collapse upon expiration. 
C) The hydrophobic portion of the DPPC repel air,forcing the alveoli space open. 
D) The choline portion of the molecule is bulky,thus increasing surface area of alveoli. 
E) None of the above explain the mechanism.

Question 9

Which of the following segments of the integral membrane protein glycophorin most likely contains the membrane-spanning sequence?

Accepted Answer

A) LSTTEVAMHTTTSSSVSKSY 
B) SQTNDTHKRDTYAATPRA 
C) VSEISVRTVYPPEEETGE 
D) ITLIIFGVMAGVIGTILLI 
E) YGIRRLIKKSPSDVKPLP 
A) LSTTEVAMHTTTSSSVSKSY 
B) SQTNDTHKRDTYAATPRA 
C) VSEISVRTVYPPEEETGE 
D) ITLIIFGVMAGVIGTILLI 
E) YGIRRLIKKSPSDVKPLP

Question 10

Botox is used cosmetically to reduce wrinkles for a limited time interval.The function of Botox is described by which of the following?

Accepted Answer

A) Botox inhibits function of the hemagglutinin tag. 
B) Botox relaxes small muscles by cleaving the leader peptide prior protein folding. 
C) Botox functions by inhibiting function of the SNARE protein. 
D) Botox functions by inhibiting the lysosomal protease cathepsin D. 
E) None of the above describes the function of Botox. 
A) Botox inhibits function of the hemagglutinin tag. 
B) Botox relaxes small muscles by cleaving the leader peptide prior protein folding. 
C) Botox functions by inhibiting function of the SNARE protein. 
D) Botox functions by inhibiting the lysosomal protease cathepsin D. 
E) None of the above describes the function of Botox.

Question 11

Rank the melting points of the following fatty acids from highest to lowest:
(1) cis-oleic(18:1)
(2) trans-oleic (18:1)
(3) linoleic (18:2) 
(4) steraic (18:0)
(5) palmitic (16:0)

Accepted Answer

A) 1 > 2 > 3 > 5 > 4 
B) 4 > 5 > 2 > 1 > 3 
C) 4 > 5 > 3 > 2 > 1 
D) 5 > 4 > 2 > 1 > 3 
E) none of the above 
A) 1 > 2 > 3 > 5 > 4 
B) 4 > 5 > 2 > 1 > 3 
C) 4 > 5 > 3 > 2 > 1 
D) 5 > 4 > 2 > 1 > 3 
E) none of the above

Question 12

Lipid bilayers with high concentrations of gangliosides are rare.Which of the following explanations is correct?

Accepted Answer

A) The hydrophobic tails on gangliosides form a conical shape rather than a cylindrical shape making close packing difficult. 
B) Gangliosides contain large headgroups making close packing difficult. 
C) Gangliosides contain trans fatty acids resulting in a bent hydrophobic tail making close packing difficult. 
D) All of the above are correct. 
E) None of the above is correct. 
A) The hydrophobic tails on gangliosides form a conical shape rather than a cylindrical shape making close packing difficult. 
B) Gangliosides contain large headgroups making close packing difficult. 
C) Gangliosides contain trans fatty acids resulting in a bent hydrophobic tail making close packing difficult. 
D) All of the above are correct. 
E) None of the above is correct.

Question 13

Matching

-Eicosanoids are 20-carbon compounds derived from ______.

Accepted Answer

A)  amphiphiles 
B)  vitamin D 
C)  arachidonic acid 
D)  phosphatidylethanolamine 
E)  sterol
F) gangliosides
G) phosphatidylcholine
H) glycerophospholipids
I) sphingomyelins
J) cholesterol
K) triacylglycerols
L) plasmalogen
M) nonpolar 
A)  amphiphiles 
B)  vitamin D 
C)  arachidonic acid 
D)  phosphatidylethanolamine 
E)  sterol
F) gangliosides
G) phosphatidylcholine
H) glycerophospholipids
I) sphingomyelins
J) cholesterol
K) triacylglycerols
L) plasmalogen
M) nonpolar

Question 14

N-terminal signal peptides function to direct proteins

Accepted Answer

A) destined for secretion. 
B) to the endoplasmic reticulum. 
C) destined to be part of the lysosomes. 
D) all of the above 
E) none of the above 
A) destined for secretion. 
B) to the endoplasmic reticulum. 
C) destined to be part of the lysosomes. 
D) all of the above 
E) none of the above

Question 15

Which of the following lipids would NOT likely be found in a lipid raft?
(I)glycosphingolipids
(II)glycerophospholipids
(III)cholesterol
(IV)palmitoleic acid

Accepted Answer

A) I,IV 
B) I,II,IV 
C) II,IV 
D) III,IV 
E) IV 
A) I,IV 
B) I,II,IV 
C) II,IV 
D) III,IV 
E) IV

Question 16

Which of the following statements describes integral membrane proteins?
(I)They protect the contents of the cell from chaotropic agents such as urea.
(II)They are easily dissociated from the membrane by changes in pH or high salt concentration.
(III)They are held tightly in place by hydrophobic effects between the membrane and hydrophobic amino acids.

Accepted Answer

A) I,II,III 
B) I,III 
C) I 
D) II 
E) III 
A) I,II,III 
B) I,III 
C) I 
D) II 
E) III

Question 17

Cold blooded animals modulate the fatty acid composition of their membranes as a function of temperature in order to

Accepted Answer

A) adjust the membrane thickness and increase thermal insulation. 
B) maximize available fatty acids for metabolic use. 
C) ensure consistent membrane fluidity. 
D) compensate for decreasing cholesterol solubility. 
E) all of the above 
A) adjust the membrane thickness and increase thermal insulation. 
B) maximize available fatty acids for metabolic use. 
C) ensure consistent membrane fluidity. 
D) compensate for decreasing cholesterol solubility. 
E) all of the above

Question 18

A suspension of which of the following is most likely to form a liposome?
(I)fatty acids
(II)triacylglycerols
(III)glycerophospholipids
(IV)sphingomyelins

Accepted Answer

A) I,II 
B) II,III 
C) III,IV 
D) II,IV 
E) I,IV 
A) I,II 
B) II,III 
C) III,IV 
D) II,IV 
E) I,IV

Exam 9: Lipids and Biological Membranes

Matching -With respect to polarity,membrane lipids can be described as ______.

Which of the following points to the correct location of attachment for a fatty acid which would yield a ceramide?

Coated vesicles are used to ensure that the enclosed protein maintains its proper orientation.Clathrin is one type of protein used to coat vesicles.Which of the following is true regarding clathrin vesicles?

Which of the following classes of proteins associates with the membrane bilayer with the lowest energy and would therefore be most difficult to separate from the membrane?

Which of the following lipid types is the least polar?

Which of the following proteins are synthesized on free ribosomes?

Sphingolipids (I)contain a glycerol core with a phosphocholine headgroup. (II)contain a modified sphingosine. (III)often function as receptor components of membranes. (IV)function as a precursor to sterols.

Lung surfactants function to decrease the likelihood of collapse of the alveoli when air is expired.Based on your knowledge of lipids and amphipathic molecules,which of the following explains the mechanism by which the dipalmitoyl phosphatidylcholine (DPPC)can accomplish this task?

Which of the following segments of the integral membrane protein glycophorin most likely contains the membrane-spanning sequence?

Botox is used cosmetically to reduce wrinkles for a limited time interval.The function of Botox is described by which of the following?

Rank the melting points of the following fatty acids from highest to lowest: (1) cis-oleic(18:1) (2) trans-oleic (18:1) (3) linoleic (18:2) (4) steraic (18:0) (5) palmitic (16:0)

Lipid bilayers with high concentrations of gangliosides are rare.Which of the following explanations is correct?

Matching -Eicosanoids are 20-carbon compounds derived from ______.

N-terminal signal peptides function to direct proteins

Which of the following lipids would NOT likely be found in a lipid raft? (I)glycosphingolipids (II)glycerophospholipids (III)cholesterol (IV)palmitoleic acid

Cold blooded animals modulate the fatty acid composition of their membranes as a function of temperature in order to

A suspension of which of the following is most likely to form a liposome? (I)fatty acids (II)triacylglycerols (III)glycerophospholipids (IV)sphingomyelins

Introduction to the Chemistry of Life

Water

Nucleotides, nucleic Acids, and Genetic Information

Amino Acids

Proteins: Primary Structure

Proteins: Three-Dimensional Structure

Protein Function Part I: Myoglobin and Hemoglobin

Carbohydrates

Membrane Transport

Enzyme Catalysis

Enzyme Kinetics, inhibition and Control

Biochemical Signaling

Introduction to Metabolism

Glucose Catabolism

Glycogen Metabolism and Gluconeogenesis

Citric Acid Cycle

Electron Transport and Oxidative Phosphorylation

Photosynthesis

Lipid Metabolism

Amino Acid Metabolism

Mammalian Fuel Metabolism: Integration and Regulation

Nucleotide Metabolism

Nucleic Acid Structure

DNA Replication, repair and Recombination

Transcription and Rna Processing

Protein Synthesis

Regulation of Gene Expression

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