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 A

Question 2

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. C

Question 3

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 E

Question 4

I-cell disease results in psychomotor retardation, skeletal deformities and death.Which of the following is true regarding this disease?

Accepted Answer

A) The disease results in inclusion of glycosaminoglycans and glycolipids due the absence of an essential carbohydrate marker that directs the lysosomal hydrolases to the lysosome. 
B) The disease results in inclusion of glycolipids due mutations in the lysosomal hydrolases that render them inactive. 
C) The disease results in increased expression of SNARE proteins that result in vesicle fusion and exchange of glycosaminoglycans. 
D) The disease results from the lack of KDEL sequences which would normally signal their return to the ER following Golgi processing. 
E) All of the above are true. 
A) The disease results in inclusion of glycosaminoglycans and glycolipids due the absence of an essential carbohydrate marker that directs the lysosomal hydrolases to the lysosome. 
B) The disease results in inclusion of glycolipids due mutations in the lysosomal hydrolases that render them inactive. 
C) The disease results in increased expression of SNARE proteins that result in vesicle fusion and exchange of glycosaminoglycans. 
D) The disease results from the lack of KDEL sequences which would normally signal their return to the ER following Golgi processing. 
E) All of the above are true.

Question 5

Which of the following statements describes one reason that plant oils are generally healthier for human consumption than animal fats?

Accepted Answer

A) Plant oils usually contain more unsaturated fatty acids than animal fats. 
B) Plant oils usually contain more trans fatty acids than animal fats. 
C) Plant oils usually have a higher degree of saturation than animal fats. 
D) Plant oils are glycerol based rather than phospholipid based. 
E) Plant oils have shorter chain fatty acids than animal fats. 
A) Plant oils usually contain more unsaturated fatty acids than animal fats. 
B) Plant oils usually contain more trans fatty acids than animal fats. 
C) Plant oils usually have a higher degree of saturation than animal fats. 
D) Plant oils are glycerol based rather than phospholipid based. 
E) Plant oils have shorter chain fatty acids than animal fats.

Question 6

Which of the following is comprised primarily of fatty acids and other single tailed amphiphiles?

Accepted Answer

A) lipid bilayers 
B) two-dimensional membranes 
C) liposomes 
D) micelles 
E) solvent-filled vesicles 
A) lipid bilayers 
B) two-dimensional membranes 
C) liposomes 
D) micelles 
E) solvent-filled vesicles

Question 7

Identify the compound below:

Accepted Answer

A) a glycerolphospholipid 
B) sphingosine 
C) ceramide 
D) spingomylelin 
E) ganglioside 
A) a glycerolphospholipid 
B) sphingosine 
C) ceramide 
D) spingomylelin 
E) ganglioside

Question 8

Which of the following is true about membrane proteins embedded within the lipid bilayer?

Accepted Answer

A) An increased temperature of the bilayer decreases the rate of transverse diffusion of the membrane protein. 
B) They undergo transverse diffusion approximately every 5 seconds at body temperature. 
C) They undergo transverse diffusion readily at body temperature unless their movement is restricted by other cellular components. 
D) As the temperature decreases, lateral diffusion of the membrane protein is restricted in bilayers with lipids which have longer chain fatty acids and fewer double bonds. 
E) Lateral diffusion of the membrane protein occurs independent of bilayer composition and temperature. 
A) An increased temperature of the bilayer decreases the rate of transverse diffusion of the membrane protein. 
B) They undergo transverse diffusion approximately every 5 seconds at body temperature. 
C) They undergo transverse diffusion readily at body temperature unless their movement is restricted by other cellular components. 
D) As the temperature decreases, lateral diffusion of the membrane protein is restricted in bilayers with lipids which have longer chain fatty acids and fewer double bonds. 
E) Lateral diffusion of the membrane protein occurs independent of bilayer composition and temperature.

Question 9

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 10

Which of the following amino acids from an integral membrane protein would likely contact the membrane?

Accepted Answer

A) Asn 
B) Gln 
C) Glu 
D) Ala 
E) Asp 
A) Asn 
B) Gln 
C) Glu 
D) Ala 
E) Asp

Question 11

Glycosphingolipids with several attached carbohydrates (including at least one sialic acid)are called:

Accepted Answer

A) plasmalogens 
B) ceramides 
C) sphingiosides 
D) gangliosides 
E) cerebrosides 
A) plasmalogens 
B) ceramides 
C) sphingiosides 
D) gangliosides 
E) cerebrosides

Question 12

Which would be most likely to be found in the membranes of mouse brain cells?

Accepted Answer

A) cholesterol 
B) glycerolphospholipids 
C) GM1, GM2, or GM3 
D) all of the above 
E) none of the above 
A) cholesterol 
B) glycerolphospholipids 
C) GM1, GM2, or GM3 
D) all of the above 
E) none of the above

Question 13

Unsaturated fatty acids:

Accepted Answer

A) are commonly found in plants and animals 
B) usually contain a double bond with cis stereochemistry 
C) sometimes contain multiple double bonds 
D) have lower melting points than the analogous saturated fatty acids 
E) all of the above 
A) are commonly found in plants and animals 
B) usually contain a double bond with cis stereochemistry 
C) sometimes contain multiple double bonds 
D) have lower melting points than the analogous saturated fatty acids 
E) all of the above

Question 14

Considering the characteristics of common fatty acids found in animals described in the text, which of the structures shown below would you consider the most rare fatty acid if found in animals?

Accepted Answer

A) Structure A 
B) Structure B 
C) Structure C 
D) Structure D 
E) All structures would be equally rare. 
A) Structure A 
B) Structure B 
C) Structure C 
D) Structure D 
E) All structures would be equally rare.

Question 15

Matching
-The myelin sheath contains high levels of ______.

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 16

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 17

The protein that forms a transmembrane pore that allows growing polypeptides to pass through the RER membrane is called the ______.

Accepted Answer

A) signal recognition particle 
B) signal peptide 
C) docking protein 
D) translocon 
E) none of the above 
A) signal recognition particle 
B) signal peptide 
C) docking protein 
D) translocon 
E) none of the above

Question 18

Proteins which are passed from one Golgi compartment to the next in a successive fashion do so via a mechanism called____.

Accepted Answer

A) maturation 
B) cisternal progression 
C) retrograde transport 
D) anterograde transport 
E) medialgrade transport 
A) maturation 
B) cisternal progression 
C) retrograde transport 
D) anterograde transport 
E) medialgrade transport

Question 19

Cholesterol

Accepted Answer

A) incorporation into the membrane results in increased rigidity. 
B) functions as a precursor to cerebrosides. 
C) is synthesized in two-carbon units. 
D) is synthesized from steroid hormones. 
E) all of the above 
A) incorporation into the membrane results in increased rigidity. 
B) functions as a precursor to cerebrosides. 
C) is synthesized in two-carbon units. 
D) is synthesized from steroid hormones. 
E) all of the above

Question 20

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

Exam 9: Lipids and Biological Membranes

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

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

I-cell disease results in psychomotor retardation, skeletal deformities and death.Which of the following is true regarding this disease?

Which of the following statements describes one reason that plant oils are generally healthier for human consumption than animal fats?

Which of the following is comprised primarily of fatty acids and other single tailed amphiphiles?

Identify the compound below:

Which of the following is true about membrane proteins embedded within the lipid bilayer?

N-terminal signal peptides function to direct proteins

Which of the following amino acids from an integral membrane protein would likely contact the membrane?

Glycosphingolipids with several attached carbohydrates (including at least one sialic acid)are called:

Which would be most likely to be found in the membranes of mouse brain cells?

Unsaturated fatty acids:

Considering the characteristics of common fatty acids found in animals described in the text, which of the structures shown below would you consider the most rare fatty acid if found in animals?

Matching -The myelin sheath contains high levels of ______.

Which of the following proteins are synthesized on free ribosomes?

The protein that forms a transmembrane pore that allows growing polypeptides to pass through the RER membrane is called the ______.

Proteins which are passed from one Golgi compartment to the next in a successive fashion do so via a mechanism called____.

Cholesterol

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

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

Glycogen Metabolism and Gluconeogenesis

Glucose Catabolism

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

Translation

Regulation of Gene Expression

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