Question 1

A fatty acid designated w-3

Accepted Answer

A) has three double bonds. 
B) is saturated. 
C) has a double bond three carbons from the end of the chain. 
D) has a double bond three carbons from the a-carbon. 
A) has three double bonds. 
B) is saturated. 
C) has a double bond three carbons from the end of the chain. 
D) has a double bond three carbons from the a-carbon.

Question 2

The arrangement of lipid bilayers and other components is the basis for the currently widely accepted description which is called the

Accepted Answer

A) fluid model. 
B) lipid bilayer model. 
C) mosaic model. 
D) diffusion model. 
E) fluid mosaic model. 
A) fluid model. 
B) lipid bilayer model. 
C) mosaic model. 
D) diffusion model. 
E) fluid mosaic model.

Question 3

Determination of the tertiary structure of a membrane protein finds that the outer surface is composed primarily of hydrophobic residues.Which conclusion is most likely from this observation?

Accepted Answer

A) It is a lipid-anchored membrane protein. 
B) It is an integral protein. 
C) The protein must be involved in passive transport. 
D) The protein can undergo transverse diffusion. 
A) It is a lipid-anchored membrane protein. 
B) It is an integral protein. 
C) The protein must be involved in passive transport. 
D) The protein can undergo transverse diffusion.

Question 4

In a typical eukaryotic plasma membrane,

Accepted Answer

A) oligosaccharides face outward,not toward the cytosol. 
B) proteins can move within the bilayer. 
C) lipids can move and diffuse through the bilayer. 
D) some lipids can rotate within the bilayer. 
E) All of the above. 
A) oligosaccharides face outward,not toward the cytosol. 
B) proteins can move within the bilayer. 
C) lipids can move and diffuse through the bilayer. 
D) some lipids can rotate within the bilayer. 
E) All of the above.

Question 5

Margarines made from plant oils are healthier,since they are hydrogenated for spreadability.

Accepted Answer

A) True 
 B)False

Question 6

Lipids may be either hydrophobic or ________.

Accepted Answer

A) hydrophilic 
B) amphoteric 
C) inorganic 
D) amphipathic 
A) hydrophilic 
B) amphoteric 
C) inorganic 
D) amphipathic

Question 7

Which statement is false about lipid-anchored membrane proteins?

Accepted Answer

A) They are found on either leaflet of the plasma membrane. 
B) Like integral membrane proteins,they are permanently associated with the membrane. 
C) The covalent link to the membrane can involve the phosphate group of the lipid anchor. 
D) The protein portion that can be removed by treatment with phospholipase most resembles an integral membrane protein. 
A) They are found on either leaflet of the plasma membrane. 
B) Like integral membrane proteins,they are permanently associated with the membrane. 
C) The covalent link to the membrane can involve the phosphate group of the lipid anchor. 
D) The protein portion that can be removed by treatment with phospholipase most resembles an integral membrane protein.

Question 8

Tay-Sachs disease results from

Accepted Answer

A) a deficiency of GM2 
B) defective lysosomes. 
C) malfunction of cerebroside metabolism. 
D) the accumulation of GM2 
A) a deficiency of GM2 
B) defective lysosomes. 
C) malfunction of cerebroside metabolism. 
D) the accumulation of GM2

Question 9

Match each technique with its purpose.
-thin layer chromatography

Accepted Answer

A) separate fatty acid esters 
B) separate neutral lipids and phospholipids 
C) separate groups of neutral lipids 
D) lateral movement of proteins in cell membranes 
E) diacylglycerol separation based on chain length and degree of unsaturation 
A) separate fatty acid esters 
B) separate neutral lipids and phospholipids 
C) separate groups of neutral lipids 
D) lateral movement of proteins in cell membranes 
E) diacylglycerol separation based on chain length and degree of unsaturation

Question 10

Diffusion of membrane proteins was demonstrated by fusing human cells and mouse cells that had membrane proteins labeled with ________ of different colors.

Accepted Answer

A) radioactivity 
B) fluorescent dyes 
C) fluorescent antibodies 
D) fluorescent lipids 
A) radioactivity 
B) fluorescent dyes 
C) fluorescent antibodies 
D) fluorescent lipids

Question 11

Which statement is true about the most common naturally occurring fatty acids?

Accepted Answer

A) They have 50-100 carbon atoms and an even number of carbon atoms. 
B) They have 50-100 carbon atoms and an odd number of carbon atoms. 
C) They have 12-20 carbon atoms and an even number of carbon atoms. 
D) They have 12-20 carbon atoms and an odd number of carbon atoms. 
A) They have 50-100 carbon atoms and an even number of carbon atoms. 
B) They have 50-100 carbon atoms and an odd number of carbon atoms. 
C) They have 12-20 carbon atoms and an even number of carbon atoms. 
D) They have 12-20 carbon atoms and an odd number of carbon atoms.

Question 12

The toxins from cholera and whooping cough both interfere with the proper functioning of ________.

Accepted Answer

A) G proteins 
B) DNA polymerase 
C) ATP synthesis 
D) protein kinase A 
A) G proteins 
B) DNA polymerase 
C) ATP synthesis 
D) protein kinase A

Question 13

Fatty acids such as linolenate can assume a variety of steric configurations.

Accepted Answer

A) True 
 B)False

Question 14

Triacylglycerols cannot form lipid bilayers because they

Accepted Answer

A) have hydrophobic tails. 
B) do not have polar heads. 
C) cannot associate with cholesterol. 
D) have polar heads. 
E) cannot engage in hydrophobic interactions. 
A) have hydrophobic tails. 
B) do not have polar heads. 
C) cannot associate with cholesterol. 
D) have polar heads. 
E) cannot engage in hydrophobic interactions.

Question 15

When red-blood cells are treated extensively with protease most membrane proteins are broken down into small peptides.However,some proteins are very resistant to this treatment.If cleavage by protease is the only type of reaction that occurs in this treatment,how is this explained?

Accepted Answer

A) They are lipid-anchored membrane proteins. 
B) They are peripheral proteins. 
C) They contain at least 2 disulfide bonds. 
D) They are integral (intrinsic)membrane proteins. 
A) They are lipid-anchored membrane proteins. 
B) They are peripheral proteins. 
C) They contain at least 2 disulfide bonds. 
D) They are integral (intrinsic)membrane proteins.

Question 16

Which is not a similarity between active transport proteins and enzymes?

Accepted Answer

A) Both undergo conformational changes upon binding a substrate. 
B) Both are susceptible to inhibition. 
C) Both cause chemical modification to the substrate. 
D) Both can reach a saturation limit. 
A) Both undergo conformational changes upon binding a substrate. 
B) Both are susceptible to inhibition. 
C) Both cause chemical modification to the substrate. 
D) Both can reach a saturation limit.

Question 17

________ are the simplest lipids but they may be a part of or a source of many complex lipids.

Accepted Answer

A) Triglycerols 
B) Carbohydrates 
C) Terpenes 
D) Fatty acids 
E) Waxes 
A) Triglycerols 
B) Carbohydrates 
C) Terpenes 
D) Fatty acids 
E) Waxes

Question 18

Triglycerols containing only saturated long chain fatty acids tend to remain ________ at room temperature.

Accepted Answer

A) unsaturated 
B) liquid 
C) solid 
D) oils 
A) unsaturated 
B) liquid 
C) solid 
D) oils

Question 19

Which statement is not true about G proteins?

Accepted Answer

A) They are integral membrane proteins. 
B) They are multisubunit proteins consisting of α,β and γ subunits. 
C) They are slowly inactivated by their own GTPase activity. 
D) They act as transducers for hormones. 
A) They are integral membrane proteins. 
B) They are multisubunit proteins consisting of α,β and γ subunits. 
C) They are slowly inactivated by their own GTPase activity. 
D) They act as transducers for hormones.

Question 20

Which statement is true about the usual concentration of free fatty acids in cells?

Accepted Answer

A) The concentration is low because it could disrupt cell membranes. 
B) The concentration is low because fatty acids are synthesized in the extracellular fluid. 
C) The concentration is high because of the demand for fatty acids in cell membranes. 
D) The concentration is high because the mitochondria are continuously synthesizing them. 
A) The concentration is low because it could disrupt cell membranes. 
B) The concentration is low because fatty acids are synthesized in the extracellular fluid. 
C) The concentration is high because of the demand for fatty acids in cell membranes. 
D) The concentration is high because the mitochondria are continuously synthesizing them.

Exam 9: Lipids and Membranes

A fatty acid designated w-3

The arrangement of lipid bilayers and other components is the basis for the currently widely accepted description which is called the

Determination of the tertiary structure of a membrane protein finds that the outer surface is composed primarily of hydrophobic residues.Which conclusion is most likely from this observation?

In a typical eukaryotic plasma membrane,

Margarines made from plant oils are healthier,since they are hydrogenated for spreadability.

Lipids may be either hydrophobic or ________.

Which statement is false about lipid-anchored membrane proteins?

Tay-Sachs disease results from

Match each technique with its purpose. -thin layer chromatography

Diffusion of membrane proteins was demonstrated by fusing human cells and mouse cells that had membrane proteins labeled with ________ of different colors.

Which statement is true about the most common naturally occurring fatty acids?

The toxins from cholera and whooping cough both interfere with the proper functioning of ________.

Fatty acids such as linolenate can assume a variety of steric configurations.

Triacylglycerols cannot form lipid bilayers because they

When red-blood cells are treated extensively with protease most membrane proteins are broken down into small peptides.However,some proteins are very resistant to this treatment.If cleavage by protease is the only type of reaction that occurs in this treatment,how is this explained?

Which is not a similarity between active transport proteins and enzymes?

________ are the simplest lipids but they may be a part of or a source of many complex lipids.

Triglycerols containing only saturated long chain fatty acids tend to remain ________ at room temperature.

Which statement is not true about G proteins?

Which statement is true about the usual concentration of free fatty acids in cells?

Introduction to Biochemistry

Water

Amino Acids and the Primary Structures of Proteins

Proteins: Three-Dimensional Structure and Function

Properties of Enzymes

Mechanisms of Enzymes

Coenzymes and Vitamins

Carbohydrates

Introduction to Metabolism

Glycolysis

Gluconeogenesis, the Pentose Phosphate Pathway, and Glycogen Metabolism

The Citric Acid Cycle

Electron Transport and Atp Synthesis

Photosynthesis

Lipid Metabolism

Amino Acid Metabolism

Nucleotide Metabolism

Nucleic Acids

DNA Replication, repair, and Recombination

Transcription and RNA Processing

Protein Synthesis

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