Question 1

Which of the following explains why free fatty acids do not form bilayers?

Accepted Answer

A)  the width of the polar head is greater than the nonpolar tail 
B)  the width of the polar head is less than the nonpolar tail 
C)  the width of the polar head is equal to the nonpolar tail 
D)  the width of the nonpolar head is greater than the polar tail 
E)  the width of the nonpolar head is less than the polar tail 
A)  the width of the polar head is greater than the nonpolar tail 
B)  the width of the polar head is less than the nonpolar tail 
C)  the width of the polar head is equal to the nonpolar tail 
D)  the width of the nonpolar head is greater than the polar tail 
E)  the width of the nonpolar head is less than the polar tail A

Question 2

In a mixed bilayer, longer acyl chains tend to be ___ than shorter acyl chains and unsaturated acyl chains are ___ than saturated chains.

Accepted Answer

less mobile, more mobile

Question 3

___ and ___ have the appropriate geometry to form lipid bilayers while ___ tends to form micelles.

Accepted Answer

Glycerophospholipids, sphingolipids, fatty acids

Question 4

In a mixed bilayer, cholesterol restricts the movement of nearby acyl chains, thus preventing the membrane from becoming too ___. Cholesterol inserts between membrane lipids, preventing close packing, thus preventing the membrane from becoming too ___.

Accepted Answer

The answer of In a mixed bilayer, cholesterol restricts the...

Question 5

If polar amino acids are found in a membrane spanning  $\alpha$ -helical region, they are most likely _____.

Accepted Answer

A)  mutations 
B)  modified with nonpolar groups by prenylation, methylation and/or acylation 
C)  hydrogen-bonded to other polar amino acids to prevent interaction with the membrane lipids 
D)  hydrogen-bonded with hydroxyl groups of the membrane fatty acids 
E)  none of the above 
A)  mutations 
B)  modified with nonpolar groups by prenylation, methylation and/or acylation 
C)  hydrogen-bonded to other polar amino acids to prevent interaction with the membrane lipids 
D)  hydrogen-bonded with hydroxyl groups of the membrane fatty acids 
E)  none of the above

Question 6

A membrane protein in a lipid raft will ___ a membrane protein attached to the cytoskeleton will ___.

Accepted Answer

move within a relati

Question 7

The carbohydrate portion of a membrane spanning glycoprotein is found _____.

Accepted Answer

A)  spanning the membrane 
B)  on both the cytoplasmic and extracellular sides of the membrane 
C)  only on the cytoplasmic side of the membrane 
D)  only on the extracellular side of the membrane 
E)  carbohydrates are not found on membrane spanning glycoproteins 
A)  spanning the membrane 
B)  on both the cytoplasmic and extracellular sides of the membrane 
C)  only on the cytoplasmic side of the membrane 
D)  only on the extracellular side of the membrane 
E)  carbohydrates are not found on membrane spanning glycoproteins

Question 8

As temperatures grow colder with the onset of winter, animals will adapt by changing the fatty acid composition of cell membranes. What characteristics of fatty acids will be seen?

Accepted Answer

A)  longer chains with greater unsaturation 
B)  longer chains with greater saturation 
C)  shorter chains with greater unsaturation 
D)  shorter chains with greater saturation 
E)  chain length and saturation do not change in a cell membrane 
A)  longer chains with greater unsaturation 
B)  longer chains with greater saturation 
C)  shorter chains with greater unsaturation 
D)  shorter chains with greater saturation 
E)  chain length and saturation do not change in a cell membrane

Question 9

If a transmembrane domain of protein contains  $\beta$ -sheet structure, the overall structure of the transmembrane portion is likely a ____________.

Accepted Answer

A)   $\beta$ -barrel 
B)   $\beta$ -tube 
C)  $\beta$ -turn 
D)   $\beta$ -helix 
E)  none of the above 
A)   $\beta$ -barrel 
B)   $\beta$ -tube 
C)  $\beta$ -turn 
D)   $\beta$ -helix 
E)  none of the above

Question 10

Which of the following is considered an omega-3 fatty acid?

Accepted Answer

A)  9,12-Octadecadienoic acid 
B)  9,12,15-Octadecatrienoic acid 
C)  6,9,12-Octadecatrienoic acid 
D)  8,11,14-Eicosatrienoic acid 
E)  5,8,11,14-Eicosatetraenoic acid 
A)  9,12-Octadecadienoic acid 
B)  9,12,15-Octadecatrienoic acid 
C)  6,9,12-Octadecatrienoic acid 
D)  8,11,14-Eicosatrienoic acid 
E)  5,8,11,14-Eicosatetraenoic acid

Question 11

Which of the structures below is an example of an $\omega$-3 polyunsaturated fatty acid?

Accepted Answer

A)    
B)    
C)    
D)    
E)  none of the above 
A)    
B)    
C)    
D)    
E)  none of the above

Question 12

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

Accepted Answer

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

Question 13

Which fatty acid is commonly attached to proteins to allow membrane localization?

Accepted Answer

A)  eicosapentaenoic acid (EP
A)  
B)  arachidonic acid 
C)  linoleic acid 
D)  myristic acid 
E)  farnesylic acid 
A)  eicosapentaenoic acid (EP
A)  
B)  arachidonic acid 
C)  linoleic acid 
D)  myristic acid 
E)  farnesylic acid

Question 14

Which of the following alcohols is esterified to the phosphate group of glycerophospholipids?

Accepted Answer

A)  choline 
B)  ethanolamine 
C)  glycerol 
D)  serine 
E)  all of the above 
A)  choline 
B)  ethanolamine 
C)  glycerol 
D)  serine 
E)  all of the above

Question 15

Which of the following is a characteristic of integral membrane proteins?

Accepted Answer

A)  most of their movement is by lateral diffusion 
B)  transverse diffusion occurs often but rather slowly 
C)  interactions between proteins makes the membrane highly rigid 
D)  all have carbohydrates attached to the extracellular domain 
E)  none of the above 
A)  most of their movement is by lateral diffusion 
B)  transverse diffusion occurs often but rather slowly 
C)  interactions between proteins makes the membrane highly rigid 
D)  all have carbohydrates attached to the extracellular domain 
E)  none of the above

Question 16

For a saturated fatty acid, melting point _____ with increasing chain length due to a greater number of _____ interactions.

Accepted Answer

increases,

Question 17

Which of the following structures correctly represents a glycerophospholipid?

Accepted Answer

A)  
  
B)  
  
C)  
  
D)

E)  none of the above 
A)  
  
B)  
  
C)  
  
D)

E)  none of the above

Question 18

Transverse diffusion occurs ___ lateral diffusion occurs ___.

Accepted Answer

very slowl

Question 19

Which of the following aspects of membrane protein movement is explained by the fluid mosaic model?

Accepted Answer

A)  proteins that are immobile are often esterified to cholesterol via an Asp residue 
B)  proteins that are mobile only in a small area are sequestered by proteins attached to the cytoskeleton 
C)  proteins that freely diffuse through the membrane often undergo flip-flopping 
D)  proteins confined to a lipid raft are linked to phosphatidylserine via and amide bond 
E)  none of the above 
A)  proteins that are immobile are often esterified to cholesterol via an Asp residue 
B)  proteins that are mobile only in a small area are sequestered by proteins attached to the cytoskeleton 
C)  proteins that freely diffuse through the membrane often undergo flip-flopping 
D)  proteins confined to a lipid raft are linked to phosphatidylserine via and amide bond 
E)  none of the above

Exam 8: Lipids and Membranes

Which of the following explains why free fatty acids do not form bilayers?

In a mixed bilayer, longer acyl chains tend to be ___ than shorter acyl chains and unsaturated acyl chains are ___ than saturated chains.

___ and ___ have the appropriate geometry to form lipid bilayers while ___ tends to form micelles.

In a mixed bilayer, cholesterol restricts the movement of nearby acyl chains, thus preventing the membrane from becoming too ___. Cholesterol inserts between membrane lipids, preventing close packing, thus preventing the membrane from becoming too ___.

If polar amino acids are found in a membrane spanning α\alphaα -helical region, they are most likely _____.

A membrane protein in a lipid raft will ___ a membrane protein attached to the cytoskeleton will ___.

The carbohydrate portion of a membrane spanning glycoprotein is found _____.

As temperatures grow colder with the onset of winter, animals will adapt by changing the fatty acid composition of cell membranes. What characteristics of fatty acids will be seen?

If a transmembrane domain of protein contains β\betaβ -sheet structure, the overall structure of the transmembrane portion is likely a ____________.

Which of the following is considered an omega-3 fatty acid?

Which of the structures below is an example of an ω\omegaω -3 polyunsaturated fatty acid?

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

Which fatty acid is commonly attached to proteins to allow membrane localization?

Which of the following alcohols is esterified to the phosphate group of glycerophospholipids?

Which of the following is a characteristic of integral membrane proteins?

For a saturated fatty acid, melting point _____ with increasing chain length due to a greater number of _____ interactions.

Which of the following structures correctly represents a glycerophospholipid?

Transverse diffusion occurs ___ lateral diffusion occurs ___.

Which of the following aspects of membrane protein movement is explained by the fluid mosaic model?

The Chemical Basis of Life

Aqueous Chemistry

Nucleic Acid Structure and Function

Protein Structure

Protein Function

How Enzymes Work

Enzyme Kinetics and Inhibition

Membrane Transport

Signaling

Carbohydrates

Metabolism and Bioenergetics

Glucose Metabolism

The Citric Acid Cycle

Oxidative Phosphorylation

Photosynthesis

Lipid Metabolism

Nitrogen Metabolism

Regulation of Mammalian Fuel Metabolism

DNA Replication and Repair

Transcription and RNA

Protein Synthesis

Filters

In a mixed bilayer, longer acyl chains tend to be _ than shorter acyl chains and unsaturated acyl chains are _ than saturated chains.

_ and _ have the appropriate geometry to form lipid bilayers while ___ tends to form micelles.

In a mixed bilayer, cholesterol restricts the movement of nearby acyl chains, thus preventing the membrane from becoming too _. Cholesterol inserts between membrane lipids, preventing close packing, thus preventing the membrane from becoming too _.

If polar amino acids are found in a membrane spanning $\alpha$ -helical region, they are most likely _____.

A membrane protein in a lipid raft will _ a membrane protein attached to the cytoskeleton will _.

If a transmembrane domain of protein contains $\beta$ -sheet structure, the overall structure of the transmembrane portion is likely a ____________.

Which of the structures below is an example of an $\omega$ -3 polyunsaturated fatty acid?

For a saturated fatty acid, melting point _ with increasing chain length due to a greater number of _ interactions.

Transverse diffusion occurs _ lateral diffusion occurs _.