Question 1

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.

Question 2

Which of the following is not true?

Accepted Answer

A)  Receptors are often invaginated into the cell after binding to their specific molecule. 
B)  A given receptor type is present at a constant level on the outside of a cell 
C)  In certain disease states, the level of a given receptor is increased or decreased 
D)  Binding of receptors to ligands sometimes shows hyperbolic binding curves 
A)  Receptors are often invaginated into the cell after binding to their specific molecule. 
B)  A given receptor type is present at a constant level on the outside of a cell 
C)  In certain disease states, the level of a given receptor is increased or decreased 
D)  Binding of receptors to ligands sometimes shows hyperbolic binding curves

Question 3

A useful method for studying membrane proteins in place in the membrane is

Accepted Answer

A)  nuclear magnetic resonance 
B)  x-ray crystallography 
C)  treatment with mercaptoethanol 
D)  treatment with detergents 
A)  nuclear magnetic resonance 
B)  x-ray crystallography 
C)  treatment with mercaptoethanol 
D)  treatment with detergents

Question 4

When an organism uses fatty acids, the ester linkages of triacylglycerols are hydrolyzed by enzymes called _____.

Accepted Answer

A)  transferases 
B)  lipases 
C)  ligases 
D)  isomerases 
A)  transferases 
B)  lipases 
C)  ligases 
D)  isomerases

Question 5

Aspirin produces most of its analgesic effects by

Accepted Answer

A)  binding to the plasma membrane of nerve cells 
B)  inhibiting the synthesis of vitamin A 
C)  inhibiting the synthesis of phospholipids 
D)  inhibiting the synthesis of prostaglandins 
A)  binding to the plasma membrane of nerve cells 
B)  inhibiting the synthesis of vitamin A 
C)  inhibiting the synthesis of phospholipids 
D)  inhibiting the synthesis of prostaglandins

Question 6

Which of the following methods of transport across a membrane does not require a protein?

Accepted Answer

A)  Passive transport 
B)  Facilitated transport 
C)  Active Transport 
D)  Simple diffusion 
E)  they all require a protein 
A)  Passive transport 
B)  Facilitated transport 
C)  Active Transport 
D)  Simple diffusion 
E)  they all require a protein

Question 7

What does amphipathic mean?

Accepted Answer

A)  having both positive and negative charges 
B)  having both acid and base properties 
C)  having both hydrophilic and hydrophobic regions 
D)  having two stereoisomers 
A)  having both positive and negative charges 
B)  having both acid and base properties 
C)  having both hydrophilic and hydrophobic regions 
D)  having two stereoisomers

Question 8

Which of the following compounds yields the most energy per gram?

Accepted Answer

A)  triacylglycerols 
B)  carbohydrates 
C)  proteins 
D)  They all yield about the same amount of energy per gram. 
A)  triacylglycerols 
B)  carbohydrates 
C)  proteins 
D)  They all yield about the same amount of energy per gram.

Question 9

How do the membranes of plant and animal cells compare?

Accepted Answer

A)  Animal cell membranes tend to be more rigid than those of plant cells. 
B)  Animal cell membranes tend to be more fluid than those of plant cells. 
C)  Animal cell membranes tend to be more asymmetric than those of plant cells. 
D)  Animal cell membranes tend to be more symmetric than those of plant cells. 
A)  Animal cell membranes tend to be more rigid than those of plant cells. 
B)  Animal cell membranes tend to be more fluid than those of plant cells. 
C)  Animal cell membranes tend to be more asymmetric than those of plant cells. 
D)  Animal cell membranes tend to be more symmetric than those of plant cells.

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

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 12

In the operation of the sodium-potassium pump

Accepted Answer

A)  conformational changes in membrane proteins are inhibited 
B)  the ions involved bind to the lipid portion of the membrane 
C)  a membrane protein is phosphorylated with ATP as the source of the phosphate group 
D)  a membrane protein is phosphorylated with ADP as the source of the phosphate group 
A)  conformational changes in membrane proteins are inhibited 
B)  the ions involved bind to the lipid portion of the membrane 
C)  a membrane protein is phosphorylated with ATP as the source of the phosphate group 
D)  a membrane protein is phosphorylated with ADP as the source of the phosphate group

Question 13

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 14

How does cholesterol affect membrane fluidity?

Accepted Answer

A)  It tends to increase the fluidity. 
B)  It tends to decrease the fluidity. 
C)  It doesn't have any specific effect on fluidity. 
D)  membranes don't have cholesterol 
A)  It tends to increase the fluidity. 
B)  It tends to decrease the fluidity. 
C)  It doesn't have any specific effect on fluidity. 
D)  membranes don't have cholesterol

Question 15

Which of the following is a metabolic precursor of prostaglandins & leukotrienes?

Accepted Answer

A)  vitamin A. 
B)  arachidonic acid. 
C)  sphingomyelin. 
D)  cholesterol. 
A)  vitamin A. 
B)  arachidonic acid. 
C)  sphingomyelin. 
D)  cholesterol.

Question 16

Vitamin E has all of the following properties, except :

Accepted Answer

A)  It is an antioxidant. 
B)  It can be made in the sunshine. 
C)  It is essential for at least some mammal's fertility. 
D)  It is often a component of membranes. 
E)  All of these describe vitamin E. 
A)  It is an antioxidant. 
B)  It can be made in the sunshine. 
C)  It is essential for at least some mammal's fertility. 
D)  It is often a component of membranes. 
E)  All of these describe vitamin E.

Question 17

Which of the following treatments would be most useful in separating an integral membrane protein from the lipid component of a cell membrane?

Accepted Answer

A)  Change the pH. 
B)  Add a salt. 
C)  Add a detergent. 
D)  Add a mixture of proteases. 
E)  None of these. You can't separate an integral membrane protein from the lipid. 
A)  Change the pH. 
B)  Add a salt. 
C)  Add a detergent. 
D)  Add a mixture of proteases. 
E)  None of these. You can't separate an integral membrane protein from the lipid.

Question 18

With what compound are fatty acids reacted to make a fat or oil?

Accepted Answer

A)  cholesterol 
B)  glycerol 
C)  sphinganine 
D)  ceramide 
A)  cholesterol 
B)  glycerol 
C)  sphinganine 
D)  ceramide

Question 19

Which property has not been observed for membrane proteins?

Accepted Answer

A)  being degraded for energy during biological pathways 
B)  transport of substances into and out of the cell 
C)  catalysis (enzymatic activity) 
D)  acting as a receptor 
A)  being degraded for energy during biological pathways 
B)  transport of substances into and out of the cell 
C)  catalysis (enzymatic activity) 
D)  acting as a receptor

Question 20

Which of the following statements concerning active transport is true?

Accepted Answer

A)  It takes place in the same direction as a concentration gradient. 
B)  It requires no expenditure of energy by the cell. 
C)  It can be compared to water running downhill. 
D)  A membrane-associate protein must be involved. 
A)  It takes place in the same direction as a concentration gradient. 
B)  It requires no expenditure of energy by the cell. 
C)  It can be compared to water running downhill. 
D)  A membrane-associate protein must be involved.

Exam 8: Lipids and Proteins Are Associated in Biological Membranes

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

Which of the following is not true?

A useful method for studying membrane proteins in place in the membrane is

When an organism uses fatty acids, the ester linkages of triacylglycerols are hydrolyzed by enzymes called _____.

Aspirin produces most of its analgesic effects by

Which of the following methods of transport across a membrane does not require a protein?

What does amphipathic mean?

Which of the following compounds yields the most energy per gram?

How do the membranes of plant and animal cells compare?

The mechanism of membrane transport may involve the following:

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

In the operation of the sodium-potassium pump

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?

How does cholesterol affect membrane fluidity?

Which of the following is a metabolic precursor of prostaglandins & leukotrienes?

Vitamin E has all of the following properties, except :

Which of the following treatments would be most useful in separating an integral membrane protein from the lipid component of a cell membrane?

With what compound are fatty acids reacted to make a fat or oil?

Which property has not been observed for membrane proteins?

Which of the following statements concerning active transport is true?

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 the 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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