Question 1

In phosphoglycerides, the fatty acids are linked to the glycerol backbone by ______________ linkages.

Accepted Answer

ester

Question 2

How many molecules thick are membranes?

Accepted Answer

A)  one 
B)  two 
C)  infinite 
D)  varying thickness, depending on structure 
E)  None of the answers is correct. 
A)  one 
B)  two 
C)  infinite 
D)  varying thickness, depending on structure 
E)  None of the answers is correct. B

Question 3

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. D

Question 4

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 5

Which of the following helps regulate membrane fluidity in animals?

Accepted Answer

A)  proteins 
B)  cholesterol 
C)  ATP 
D)  magnesium ions 
E)  None of the answers is correct. 
A)  proteins 
B)  cholesterol 
C)  ATP 
D)  magnesium ions 
E)  None of the answers is correct.

Question 6

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 7

Which of the following is true?

Accepted Answer

A)  Membranes are lipid bilayers. 
B)  Membrane lipids have both hydrophobic and hydrophilic properties. 
C)  Many membranes are electrically polarized. 
D)  All of the answers are correct. 
E)  A and B. 
A)  Membranes are lipid bilayers. 
B)  Membrane lipids have both hydrophobic and hydrophilic properties. 
C)  Many membranes are electrically polarized. 
D)  All of the answers are correct. 
E)  A and B.

Question 8

Draw a cross-section of a micelle and a membrane bilayer.

Accepted Answer

Micelles are spherical arrangements in w

Question 9

Why do most phospholipids preferentially form sheets instead of micelles?

Accepted Answer

The two tails of pho

Question 10

What is the function of prostaglandin H2 synthase-1? How does its position in the membrane facilitate its activity?

Accepted Answer

Prostaglandin H₂ synthase-1 converts arac

Question 11

What membrane components contain carbohydrates?

Accepted Answer

A)  lipid-linked proteins 
B)  cholesterol 
C)  integral membrane proteins in contact with the cytoplasm 
D)  phosphatidylserine 
E)  glycolipids 
A)  lipid-linked proteins 
B)  cholesterol 
C)  integral membrane proteins in contact with the cytoplasm 
D)  phosphatidylserine 
E)  glycolipids

Question 12

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

Accepted Answer

Membrane potential p

Question 13

___________________ membrane proteins are bound to membranes primarily by electrostatic and hydrogen bond interactions with the head groups of lipids.

Accepted Answer

The answer of ___________________ membrane proteins are bound to membranes...

Question 14

The rate of diffusion is such that a phospholipid molecule can travel from one end of a bacterium to the other in _______________ of time.

Accepted Answer

The answer of The rate of diffusion is such that...

Question 15

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 16

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 17

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 18

________________ is a membrane lipid composed of sphingosine, fatty acid, and a simple sugar like glucose or galactose.

Accepted Answer

The answer of ________________ is a membrane lipid composed of...

Question 19

What property is used to determine the probability that a segment of a protein will be found embedded in a membrane?

Accepted Answer

A)  hydropathy 
B)  polarity 
C)  acidity 
D)  entropy 
E)  solvation 
A)  hydropathy 
B)  polarity 
C)  acidity 
D)  entropy 
E)  solvation

Question 20

What is the number of carbons found in the most commonly observed fatty acids?

Accepted Answer

A)  12 or 14 
B)  14 or 16 
C)  16 or 18 
D)  18 or 20 
E)  20 or 22 
A)  12 or 14 
B)  14 or 16 
C)  16 or 18 
D)  18 or 20 
E)  20 or 22

Exam 12: Lipids and Cell Membranes

In phosphoglycerides, the fatty acids are linked to the glycerol backbone by ______________ linkages.

How many molecules thick are membranes?

Which of the following membranes would be the most fluid?

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

Which of the following helps regulate membrane fluidity in animals?

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

Which of the following is true?

Draw a cross-section of a micelle and a membrane bilayer.

Why do most phospholipids preferentially form sheets instead of micelles?

What is the function of prostaglandin H2 synthase-1? How does its position in the membrane facilitate its activity?

What membrane components contain carbohydrates?

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

___________________ membrane proteins are bound to membranes primarily by electrostatic and hydrogen bond interactions with the head groups of lipids.

The rate of diffusion is such that a phospholipid molecule can travel from one end of a bacterium to the other in _______________ of time.

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

Membranes are primarily comprised of

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

________________ is a membrane lipid composed of sphingosine, fatty acid, and a simple sugar like glucose or galactose.

What property is used to determine the probability that a segment of a protein will be found embedded in a membrane?

What is the number of carbons found in the most commonly observed fatty acids?

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 is the function of prostaglandin H₂ synthase-1? How does its position in the membrane facilitate its activity?