Question 1

What characteristic is most used to define lipids?

Accepted Answer

A)  ionic charge 
B)  melting point 
C)  solubility 
D)  ability to bind metal ions 
A)  ionic charge 
B)  melting point 
C)  solubility 
D)  ability to bind metal ions

Question 2

How many hydroxyl groups does a molecule of glycerol have?

Accepted Answer

A)  none 
B)  1 
C)  2 
D)  3 
E)  4 
A)  none 
B)  1 
C)  2 
D)  3 
E)  4

Question 3

Plants need cholesterol in their membranes to counteract the rigidity of the cell wall.

Accepted Answer

A) True 
 B)False

Question 4

I find that briefly washing cells in a buffered solution at pH 11 is effective for isolating a cell membrane-associated hormone receptor. (A standard growth solution for the cells is pH 7.) Which of following best fits this description?

Accepted Answer

A)  This is an integral membrane protein that completely traverses the cell membrane. 
B)  This is an integral membrane protein that only penetrates one leaf of the cell membrane. 
C)  This is a peripheral membrane protein that probably interacts with membrane phospholipids using aspartate-mediated salt bridges. 
D)  This is a peripheral membrane protein that probably interacts with membrane phospholipids using lysine-mediated salt bridges. 
A)  This is an integral membrane protein that completely traverses the cell membrane. 
B)  This is an integral membrane protein that only penetrates one leaf of the cell membrane. 
C)  This is a peripheral membrane protein that probably interacts with membrane phospholipids using aspartate-mediated salt bridges. 
D)  This is a peripheral membrane protein that probably interacts with membrane phospholipids using lysine-mediated salt bridges.

Question 5

Exhibit 8A
  
-Refer to Exhibit 8A. Which protein would likely be involved in a channel?

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
E)  You cannot tell from the diagram. 
A)  1 
B)  2 
C)  3 
D)  4 
E)  You cannot tell from the diagram.

Question 6

Which of the following lipids is not found in biological membranes?

Accepted Answer

A)  triacylglycerols 
B)  phosphoacylglycerols 
C)  glycolipids 
D)  cholesterol 
A)  triacylglycerols 
B)  phosphoacylglycerols 
C)  glycolipids 
D)  cholesterol

Question 7

In the fluid mosaic model of membrane structure

Accepted Answer

A)  the proteins are specifically bonded to the lipids 
B)  the proteins "float" in the lipid bilayer 
C)  the proteins are sandwiched between the lipid molecules 
D)  the lipids are sandwiched between the protein molecules 
A)  the proteins are specifically bonded to the lipids 
B)  the proteins "float" in the lipid bilayer 
C)  the proteins are sandwiched between the lipid molecules 
D)  the lipids are sandwiched between the protein molecules

Question 8

Which of the following alcohols is never found in phosphatides?

Accepted Answer

A)  Ethanolamine 
B)  Serine 
C)  Inositol 
D)  Sugars 
E)  All of these can be components of phosphatides. 
A)  Ethanolamine 
B)  Serine 
C)  Inositol 
D)  Sugars 
E)  All of these can be components of phosphatides.

Question 9

Phospholipids are particularly important in these structures:

Accepted Answer

A)  Membranes. 
B)  Lipoproteins. 
C)  The brain and nervous system. 
D)  Membranes, the brain and the nervous system. 
E)  All of these are correct. 
A)  Membranes. 
B)  Lipoproteins. 
C)  The brain and nervous system. 
D)  Membranes, the brain and the nervous system. 
E)  All of these are correct.

Question 10

The mechanism of membrane transport may involve the following:

Accepted Answer

A)  ATP hydrolysis. 
B)  Conformation change of membrane proteins. 
C)  Phosphorylation or dephosphorylation of membrane proteins. 
D)  ATP hydrolysis and conformation change of membrane proteins. 
E)  All of these are correct. 
A)  ATP hydrolysis. 
B)  Conformation change of membrane proteins. 
C)  Phosphorylation or dephosphorylation of membrane proteins. 
D)  ATP hydrolysis and conformation change of membrane proteins. 
E)  All of these are correct.

Question 11

Which of the following groups is not present in a cerebroside?

Accepted Answer

A)  Sphingosine 
B)  Fatty acid 
C)  Phosphate 
D)  Sugar 
E)  All of these can be components of cerebrosides. 
A)  Sphingosine 
B)  Fatty acid 
C)  Phosphate 
D)  Sugar 
E)  All of these can be components of cerebrosides.

Question 12

Which of the following is not a product of saponification of a triglyceride?

Accepted Answer

A)  Long chain fatty alcohols. 
B)  The salt of the fatty acids. 
C)  Soaps. 
D)  Glycerol. 
E)  All of these are products of saponification. 
A)  Long chain fatty alcohols. 
B)  The salt of the fatty acids. 
C)  Soaps. 
D)  Glycerol. 
E)  All of these are products of saponification.

Question 13

Biological waxes are composed of

Accepted Answer

A)  glycerol and only one fatty acid. 
B)  glycerol and two fatty acids 
C)  a fatty acid and a long-chain alcohol. 
D)  cholesterol and a fatty acid. 
A)  glycerol and only one fatty acid. 
B)  glycerol and two fatty acids 
C)  a fatty acid and a long-chain alcohol. 
D)  cholesterol and a fatty acid.

Question 14

Where can membrane proteins be located?

Accepted Answer

A)  entirely within the membrane 
B)  on the surface of the membrane 
C)  in either position 
D)  The position of membrane proteins has never been determined. 
A)  entirely within the membrane 
B)  on the surface of the membrane 
C)  in either position 
D)  The position of membrane proteins has never been determined.

Question 15

Lipids differ from most other biomolecules because they are defined on the basis of solubility, rather than on their chemical structure.

Accepted Answer

A) True 
 B)False

Question 16

Which of the following is true?

Accepted Answer

A)  Fatty acids with trans double bonds may be particularly unhealthy because they increase the ratio of LDLs to HDLs. 
B)  A fatty acid with 14 carbons and one trans double bond will behave more like a saturated fatty acid with 14 carbons than will an unsaturated fatty acid with a cis double bond. 
C)  Fatty acids with trans double bonds can be formed by hydrogenation reaction of polyunssaturated fatty acids 
D)  fatty acids with trans double bonds tend to have higher melting points than those with cis double bonds all else being equal 
E)  All of these are correct 
A)  Fatty acids with trans double bonds may be particularly unhealthy because they increase the ratio of LDLs to HDLs. 
B)  A fatty acid with 14 carbons and one trans double bond will behave more like a saturated fatty acid with 14 carbons than will an unsaturated fatty acid with a cis double bond. 
C)  Fatty acids with trans double bonds can be formed by hydrogenation reaction of polyunssaturated fatty acids 
D)  fatty acids with trans double bonds tend to have higher melting points than those with cis double bonds all else being equal 
E)  All of these are correct

Question 17

The vitamin classified as fat soluble rather than water soluble is

Accepted Answer

A)  vitamin A 
B)  vitamin B1 
C)  vitamin B6 
D)  vitamin C 
A)  vitamin A 
B)  vitamin B1 
C)  vitamin B6 
D)  vitamin C

Question 18

Which of the following is not true?

Accepted Answer

A)  Plant oils are favored in the diet because they generally contain more unsaturated fats than found in animal fats. 
B)  Unsaturated fatty acids are healthier for humans than saturated ones 
C)  Heart disease can be correlated with diets high in saturated fatty acids 
D)  Unsaturated fatty acids lead to higher levels of LDL than saturated fatty acids do 
A)  Plant oils are favored in the diet because they generally contain more unsaturated fats than found in animal fats. 
B)  Unsaturated fatty acids are healthier for humans than saturated ones 
C)  Heart disease can be correlated with diets high in saturated fatty acids 
D)  Unsaturated fatty acids lead to higher levels of LDL than saturated fatty acids do

Question 19

Liposomes are

Accepted Answer

A)  artificial membrane-bounded structures used to deliver medications. 
B)  single-layered membranes. 
C)  mixed micelles involved in cholesterol transport among cells. 
D)  bilayers with the hydrophobic regions on the outside. 
A)  artificial membrane-bounded structures used to deliver medications. 
B)  single-layered membranes. 
C)  mixed micelles involved in cholesterol transport among cells. 
D)  bilayers with the hydrophobic regions on the outside.

Question 20

What kinds of bonds do lipase break in order to release fatty acids from triacylglycerols?

Accepted Answer

A)  esters 
B)  carbon-carbon single bonds 
C)  carbon-carbon double bonds 
D)  There are no fatty acids in triacylglycerols to release. 
A)  esters 
B)  carbon-carbon single bonds 
C)  carbon-carbon double bonds 
D)  There are no fatty acids in triacylglycerols to release.

Exam 8: Lipids and Proteins Are Associated in Biological Membranes

What characteristic is most used to define lipids?

How many hydroxyl groups does a molecule of glycerol have?

Plants need cholesterol in their membranes to counteract the rigidity of the cell wall.

I find that briefly washing cells in a buffered solution at pH 11 is effective for isolating a cell membrane-associated hormone receptor. (A standard growth solution for the cells is pH 7.) Which of following best fits this description?

Exhibit 8A -Refer to Exhibit 8A. Which protein would likely be involved in a channel?

Which of the following lipids is not found in biological membranes?

In the fluid mosaic model of membrane structure

Which of the following alcohols is never found in phosphatides?

Phospholipids are particularly important in these structures:

The mechanism of membrane transport may involve the following:

Which of the following groups is not present in a cerebroside?

Which of the following is not a product of saponification of a triglyceride?

Biological waxes are composed of

Where can membrane proteins be located?

Lipids differ from most other biomolecules because they are defined on the basis of solubility, rather than on their chemical structure.

Which of the following is true?

The vitamin classified as fat soluble rather than water soluble is

Which of the following is not true?

Liposomes are

What kinds of bonds do lipase break in order to release fatty acids from triacylglycerols?

Biochemistry and the Organization of Cells

Water: the Solvent for Biochemical Reactions

Amino Acids and Peptides

The Three-Dimensional Structure of Proteins

Protein Purification and Characterization Techniques

The Behavior of Proteins: Enzymes

The Behavior of Proteins: Enzymes, Mechanisms, and Control

Nucleic Acids: How Structure Conveys Information

Biosynthesis of Nucleic Acids: Replication

Transcription of the Genetic Code: Biosynthesis of RNA

Protein Synthesis: Translation of the Genetic Message

Nucleic Acid Biotechnology Techniques

Viruses, Cancer, and Immunology

The Importance of Energy Changes and Electron Transfer in Metabolism

Carbohydrates

Glycolysis

Storage Mechanisms and Control in Carbohydrate Metabolism

The Citric Acid Cycle

Electron Transport and Oxidative Phosphorylation

Lipid Metabolism

Photosynthesis

The Metabolism of Nitrogen

Integration of Metabolism: Cellular Signaling

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