Question 1

Draw and label a typical phospholipid.

Accepted Answer

The phospholipid drawn should resemble F

Question 2

What complex is observed between cholesterol and membrane phospholipids?

Accepted Answer

A)  salt bridge 
B)  clathrate 
C)  lipid raft 
D)  phospholipid domain 
E)  None of the answers is correct. 
A)  salt bridge 
B)  clathrate 
C)  lipid raft 
D)  phospholipid domain 
E)  None of the answers is correct.

Question 3

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 4

Which of the following is NOT correct concerning the structure given?

Accepted Answer

A)  It is a component of biological membranes. 
B)  It is amphipathic. 
C)  It is a sphingolipid. 
D)  It is a phosphoglyceride. 
E)  It is phosphatidyl choline. 
A)  It is a component of biological membranes. 
B)  It is amphipathic. 
C)  It is a sphingolipid. 
D)  It is a phosphoglyceride. 
E)  It is phosphatidyl choline.

Question 5

Which of the following membrane-bound organelles is thought to have evolved from bacteria by endosymbosis?

Accepted Answer

A)  peroxisomes 
B)  mitochondria 
C)  cell walls 
D)  nuclei 
E)  endoplasmic reticulum 
A)  peroxisomes 
B)  mitochondria 
C)  cell walls 
D)  nuclei 
E)  endoplasmic reticulum

Question 6

__________________ contain a double bond three carbons from the distal end of the fatty acid.

Accepted Answer

The answer of __________________ contain a double bond three carbons...

Question 7

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 8

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

Accepted Answer

Lipid vesi

Question 9

Ionized fatty acids readily form ______________ in aqueous solutions.

Accepted Answer

The answer of Ionized fatty acids readily form ______________ in...

Question 10

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.

Question 11

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 12

Some proteins are anchored to the membrane by being covalently attached to a _______________ group by a thioester linkage to a specific (non-C-terminal) cysteine residue.

Accepted Answer

The answer of Some proteins are anchored to the membrane...

Question 13

The temperature at which a phospholipid membrane transitions from a rigid to a fluid state is referred to as _______________.

Accepted Answer

T_m, or melt

Question 14

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

Accepted Answer

Liposomes are spherical structures of li

Question 15

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

Accepted Answer

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

Question 16

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 17

Which of the following statements is consistent with the structure of biological membranes?

Accepted Answer

A)  All membrane proteins are integral and associate with the hydrophobic region of the membrane. 
B)  Both proteins and lipids readily undergo transverse ("flip-flop") diffusion from the inside to the outside of the membrane. 
C)  Membranes are symmetric. 
D)  The membrane lipids self-assemble to form the lipid bilayer. 
E)  A biological membrane consists of proteins sandwiched between two layers of lipids, which are referred to as a lipid bilayer. 
A)  All membrane proteins are integral and associate with the hydrophobic region of the membrane. 
B)  Both proteins and lipids readily undergo transverse ("flip-flop") diffusion from the inside to the outside of the membrane. 
C)  Membranes are symmetric. 
D)  The membrane lipids self-assemble to form the lipid bilayer. 
E)  A biological membrane consists of proteins sandwiched between two layers of lipids, which are referred to as a lipid bilayer.

Question 18

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 19

What force(s) stabilize(s) the lipid bilayers?

Accepted Answer

A)  van der Waals interactions 
B)  electrostatic and hydrogen bonding between the polar heads and surrounding water 
C)  covalent bonds between the lipids and membrane proteins 
D)  van der Waals interactions and electrostatic and hydrogen bonding between the polar heads and surrounding water 
E)  electrostatic and hydrogen bonding between the polar heads and surrounding water and covalent bonds between the lipids and membrane proteins 
A)  van der Waals interactions 
B)  electrostatic and hydrogen bonding between the polar heads and surrounding water 
C)  covalent bonds between the lipids and membrane proteins 
D)  van der Waals interactions and electrostatic and hydrogen bonding between the polar heads and surrounding water 
E)  electrostatic and hydrogen bonding between the polar heads and surrounding water and covalent bonds between the lipids and membrane proteins

Question 20

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

Accepted Answer

The membrane should be depicted as a bil

Exam 12: Lipids and Cell Membranes

Draw and label a typical phospholipid.

What complex is observed between cholesterol and membrane phospholipids?

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

Which of the following is NOT correct concerning the structure given?

Which of the following membrane-bound organelles is thought to have evolved from bacteria by endosymbosis?

__________________ contain a double bond three carbons from the distal end of the fatty acid.

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

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

Ionized fatty acids readily form ______________ in aqueous solutions.

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

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

Some proteins are anchored to the membrane by being covalently attached to a _______________ group by a thioester linkage to a specific (non-C-terminal) cysteine residue.

The temperature at which a phospholipid membrane transitions from a rigid to a fluid state is referred to as _______________.

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

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

The most common motif found in membrane spanning proteins is

Which of the following statements is consistent with the structure of biological membranes?

What important property is conferred on membranes by transport systems?

What force(s) stabilize(s) the lipid bilayers?

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

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

Oxidative Phosphorylation

Catalytic Strategies

Regulatory Strategies

Carbohydrates

Membrane Channels and Pumps

Signal-Transduction Pathways

Metabolism: Basic Concepts and Design

Glycolysis and Gluconeogenesis

The Citric Acid Cycle

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?