Question 1

What is receptor-mediated endocytosis?

Accepted Answer

Receptor-mediated endocytosis

Question 2

What are the primary structural differences between phospholipids constructed from a glycerol platform and those from sphingosine?

Accepted Answer

Phospholipids derived from glycerol are

Question 3

What substance inhibits prostaglandin H2 synthase-1 by blocking the channel through which the substrate,arachidonate,travels?

Accepted Answer

A)  acetaminophen 
B)  Celebrex 
C)  ibuprofen 
D)  Vioxx 
E)  acetylsalicylic acid 
A)  acetaminophen 
B)  Celebrex 
C)  ibuprofen 
D)  Vioxx 
E)  acetylsalicylic acid

Question 4

What important property is conferred on membranes by transport systems?

Accepted Answer

A)  asymmetry 
B)  selective permeability 
C)  bilayer 
D)  amphipathic nature 
E)  None of the answers is correct. 
A)  asymmetry 
B)  selective permeability 
C)  bilayer 
D)  amphipathic nature 
E)  None of the answers is correct.

Question 5

Carbohydrate residues attached to the membrane lipids are almost always

Accepted Answer

A)  positioned on the intracellular side of the membrane. 
B)  positioned on the inside center of the bilayer. 
C)  positioned on the extracellular side of the membrane. 
D)  positioned equally on both sides of the membrane. 
E)  also covalently attached to membrane proteins. 
A)  positioned on the intracellular side of the membrane. 
B)  positioned on the inside center of the bilayer. 
C)  positioned on the extracellular side of the membrane. 
D)  positioned equally on both sides of the membrane. 
E)  also covalently attached to membrane proteins.

Question 6

Membranes are primarily comprised of

Accepted Answer

A)  lipids. 
B)  proteins. 
C)  carbohydrates. 
D)  All of the answers are correct. 
E)  A and B. 
A)  lipids. 
B)  proteins. 
C)  carbohydrates. 
D)  All of the answers are correct. 
E)  A and B.

Question 7

Membranes carry out what functions due to their electrically polarized structure?

Accepted Answer

Membrane potential p

Question 8

What are the two systems for naming the positions of the double bonds? Provide examples.

Accepted Answer

One system refers to the double bond rel

Question 9

Draw and label a typical phospholipid.

Accepted Answer

The phospholipid drawn should resemble F

Question 10

What are some molecules that form the polar head group of a phospholipid (bound to the phosphate)? Provide several examples.

Accepted Answer

Examples of head gro

Question 11

What are liposomes? What are some of the current commercial applications?

Accepted Answer

Liposomes are spherical structures of li

Question 12

The degree of membrane fluidity in bacteria depends mainly on the percentage of

Accepted Answer

A)  lipids that contain sphingosine. 
B)  glycolipids. 
C)  free fatty acids. 
D)  unsaturated fatty acids. 
E)  None of the answers is correct. 
A)  lipids that contain sphingosine. 
B)  glycolipids. 
C)  free fatty acids. 
D)  unsaturated fatty acids. 
E)  None of the answers is correct.

Question 13

The most common motif found in membrane spanning proteins is

Accepted Answer

A)  $\alpha$ helices of nonpolar amino acids that pass through the membrane. 
B) $\alpha$ helices of charged amino acids that form channels via extensive hydrogen bonding. 
C)  a triple helix of $\alpha$ helices. 
D)  a helix-turn-helix arrangement of the peptide strands. 
E)  None of the answers is correct. 
A)  $\alpha$ helices of nonpolar amino acids that pass through the membrane. 
B) $\alpha$ helices of charged amino acids that form channels via extensive hydrogen bonding. 
C)  a triple helix of $\alpha$ helices. 
D)  a helix-turn-helix arrangement of the peptide strands. 
E)  None of the answers is correct.

Question 14

How do the membranes of archaea differ from bacteria and eukaryotes?

Accepted Answer

A)  The lipids do not contain a carboxylic acid ester, but instead have an ether link to the glycerol. 
B)  The alkyl chains are branched. 
C)  The stereochemistry of the central carbon of glycerol is inverted. 
D)  A and C are correct. 
E)  All the answers are correct. 
A)  The lipids do not contain a carboxylic acid ester, but instead have an ether link to the glycerol. 
B)  The alkyl chains are branched. 
C)  The stereochemistry of the central carbon of glycerol is inverted. 
D)  A and C are correct. 
E)  All the answers are correct.

Question 15

___________________ are aqueous compartments enclosed by a lipid bilayer which can be created in a laboratory.

Accepted Answer

Lipid vesi

Question 16

In addition to phospholipids and glycolipids,which of the following is a major type of membrane lipid?

Accepted Answer

A)  cholesterol 
B)  vitamin E 
C)  triacylglycerol 
D)  free fatty acids 
E)  None of the answers is correct. 
A)  cholesterol 
B)  vitamin E 
C)  triacylglycerol 
D)  free fatty acids 
E)  None of the answers is correct.

Question 17

Which of the following membranes would be the most fluid?

Accepted Answer

A)  a bilayer made of lipids with polyunsaturated 18 carbon-fatty acids 
B)  a bilayer made of lipids with saturated 18 carbon-fatty acids 
C)  a bilayer made of lipids with saturated 16 carbon-fatty acids 
D)  a bilayer made of lipids with polyunsaturated 16 carbon-fatty acids 
E)  All of the above are equivalent in fluidity. 
A)  a bilayer made of lipids with polyunsaturated 18 carbon-fatty acids 
B)  a bilayer made of lipids with saturated 18 carbon-fatty acids 
C)  a bilayer made of lipids with saturated 16 carbon-fatty acids 
D)  a bilayer made of lipids with polyunsaturated 16 carbon-fatty acids 
E)  All of the above are equivalent in fluidity.

Question 18

In animals,________________ is the key regulator of membrane fluidity.

Accepted Answer

The answer of In animals,________________ is the key regulator of...

Question 19

Draw a bilayer membrane that has both an integral and peripheral protein present.

Accepted Answer

The membrane should be depicted as a bil

Question 20

What term describes molecules that have both hydrophilic and hydrophobic moieties?

Accepted Answer

A)  amphoteric 
B)  amphiprotic 
C)  amphibian 
D)  amphipathic 
E)  None of the answers is correct. 
A)  amphoteric 
B)  amphiprotic 
C)  amphibian 
D)  amphipathic 
E)  None of the answers is correct.

Exam 12: Lipids and Cell Membranes

What is receptor-mediated endocytosis?

What are the primary structural differences between phospholipids constructed from a glycerol platform and those from sphingosine?

What substance inhibits prostaglandin H2 synthase-1 by blocking the channel through which the substrate,arachidonate,travels?

What important property is conferred on membranes by transport systems?

Carbohydrate residues attached to the membrane lipids are almost always

Membranes are primarily comprised of

Membranes carry out what functions due to their electrically polarized structure?

What are the two systems for naming the positions of the double bonds? Provide examples.

Draw and label a typical phospholipid.

What are some molecules that form the polar head group of a phospholipid (bound to the phosphate)? Provide several examples.

What are liposomes? What are some of the current commercial applications?

The degree of membrane fluidity in bacteria depends mainly on the percentage of

The most common motif found in membrane spanning proteins is

How do the membranes of archaea differ from bacteria and eukaryotes?

___________________ are aqueous compartments enclosed by a lipid bilayer which can be created in a laboratory.

In addition to phospholipids and glycolipids,which of the following is a major type of membrane lipid?

Which of the following membranes would be the most fluid?

In animals,________________ is the key regulator of membrane fluidity.

Draw a bilayer membrane that has both an integral and peripheral protein present.

What term describes molecules that have both hydrophilic and hydrophobic moieties?

Biochemistry: An Evolving Science

Protein Composition and Structure

Exploring Proteins and Proteomes

DNA, RNA, and the Flow of Genetic Information

Exploring Genes and Genomes

Exploring Evolution and Bioinformatics

Hemoglobin: a Portrait of a Protein in Action

Enzymes: Basic Concepts and Kinetics

Catalytic Strategies

Regulatory Strategies

Carbohydrates

Membrane Channels and Pumps

Signal-Transduction Pathways

Metabolism: Basic Concepts and Design

Glycolysis and Gluconeogenesis

The Citric Acid Cycle

Oxidative Phosphorylation

The Light Reactions of Photosynthesis

The Calvin Cycle and the Pentose Phosphate Pathway

Glycogen Metabolism

Fatty Acid Metabolism

Protein Turnover and Amino Acid Catabolism

The Biosynthesis of Amino Acids

Nucleotide Biosynthesis

Biosynthesis of Membrane Lipids and Steroids

The Integration of Metabolism

DNA Replication, repair, and Recombination

RNA Synthesis and Processing

Protein Synthesis

The Control of Gene Expression in Prokaryotes

The Control of Gene Expression in Eukaryotes

Sensory Systems

The Immune System

Molecular Motors

Drug Development

Filters

What substance inhibits prostaglandin H₂ synthase-1 by blocking the channel through which the substrate,arachidonate,travels?