Chapter 11 Test Bank
11-1 Which of the following phenomena will be observed if a cell's membrane is
pierced?
(a) the membrane reseals
(b) the membrane collapses
(c) a tear is formed
(d) the membrane expands - ANS - A
\11-2 The plasma membrane serves many functions, many of which depend on
the presence of specialized membrane proteins. Which of the following roles of
the plasma membrane could still occur if the bilayer were lacking these proteins?
(a) intercellular communication
(b) selective permeability
(c) cellular movement
(d) import/export of molecules - ANS - B
\11-4 Which type of lipids are the most abundant in the plasma membrane?
(a) phospholipids
(b) glycolipids
(c) sterols
(d) triacylglycerides - ANS - A
\11-6 Which of the following membrane lipids does not contain a fatty acid tail?
(a) phosphatidylcholine
(b) a glycolipid
(c) phosphatidylserine
(d) cholesterol - ANS - D
\11-7 Formation of a lipid bilayer is energetically favorable. How does this
arrangement result in higher entropy for the system, and thus make bilayer
formation energetically favorable?
(a) Polar head groups form a hydrogen-bonding network at the interface with
water.
(b) Water molecules form cagelike structures around hydrophobic molecules.
(c) Hydrogen bonds form between neighboring polar head groups in the bilayer.
(d) Fatty acid tails are highly saturated and flexible. - ANS - B
\11-8 Which of the following statements is true?
(a) Phospholipids will spontaneously form liposomes in nonpolar solvents.
(b) In eukaryotes, all membrane-enclosed organelles are surrounded by one lipid
bilayer.
(c) Membrane lipids diffuse within the plane of the membrane.
, (d) Membrane lipids frequently flip-flop between one monolayer and the other. -
ANS - C
\11-9 A bacterium is suddenly expelled from a warm human intestine into the cold
world outside. Which of the following adjustments might the bacterium make to
maintain the same level of membrane fluidity?
(a) Produce lipids with hydrocarbon tails that are longer and have fewer double
bonds.
(b) Produce lipids with hydrocarbon tails that are shorter and have more double
bonds.
(c) Decrease the amount of cholesterol in the membrane.
(d) Decrease the amount of glycolipids in the membrane. - ANS - B
\11-12 Some lipases are able to cleave the covalent bonds between the glycerol
backbone and the attached fatty acid. What final products do you expect to
accumulate through the action of the enzyme monoacylglycerol lipase?
(a) phosphoglycerol and free fatty acid
(b) sterol and glycerol
(c) free phosphate and glycerol
(d) glycerol and free fatty acid - ANS - D
\11-13 Which of the following phospholipid precursors is the most hydrophobic?
(a) triacylglycerol
(b) diacylglycerol
(c) phosphate
(d) glycerol - ANS - A
\11-14 Three phospholipids X, Y, and Z are distributed in the plasma membrane as
indicated in Figure Q11-14. For which of these phospholipids does a flippase
probably exist?
(a) X only
(b) Z only
(c) X and Y
(d) Y and Z - ANS - C
\11-15 Where does most new membrane synthesis take place in a eukaryotic cell?
(a) in the Golgi apparatus
(b) in the endoplasmic reticulum
(c) in the plasma membrane
(d) in the mitochondria
(e) on ribosomes - ANS - B
\11-16 Water molecules readily form hydrogen bonds with other polar molecules,
and when they encounter nonpolar molecules they must form hydrogen-bonding
networks with neighboring water molecules. Which of the following molecules
will cause a "cage" of water to form?
11-1 Which of the following phenomena will be observed if a cell's membrane is
pierced?
(a) the membrane reseals
(b) the membrane collapses
(c) a tear is formed
(d) the membrane expands - ANS - A
\11-2 The plasma membrane serves many functions, many of which depend on
the presence of specialized membrane proteins. Which of the following roles of
the plasma membrane could still occur if the bilayer were lacking these proteins?
(a) intercellular communication
(b) selective permeability
(c) cellular movement
(d) import/export of molecules - ANS - B
\11-4 Which type of lipids are the most abundant in the plasma membrane?
(a) phospholipids
(b) glycolipids
(c) sterols
(d) triacylglycerides - ANS - A
\11-6 Which of the following membrane lipids does not contain a fatty acid tail?
(a) phosphatidylcholine
(b) a glycolipid
(c) phosphatidylserine
(d) cholesterol - ANS - D
\11-7 Formation of a lipid bilayer is energetically favorable. How does this
arrangement result in higher entropy for the system, and thus make bilayer
formation energetically favorable?
(a) Polar head groups form a hydrogen-bonding network at the interface with
water.
(b) Water molecules form cagelike structures around hydrophobic molecules.
(c) Hydrogen bonds form between neighboring polar head groups in the bilayer.
(d) Fatty acid tails are highly saturated and flexible. - ANS - B
\11-8 Which of the following statements is true?
(a) Phospholipids will spontaneously form liposomes in nonpolar solvents.
(b) In eukaryotes, all membrane-enclosed organelles are surrounded by one lipid
bilayer.
(c) Membrane lipids diffuse within the plane of the membrane.
, (d) Membrane lipids frequently flip-flop between one monolayer and the other. -
ANS - C
\11-9 A bacterium is suddenly expelled from a warm human intestine into the cold
world outside. Which of the following adjustments might the bacterium make to
maintain the same level of membrane fluidity?
(a) Produce lipids with hydrocarbon tails that are longer and have fewer double
bonds.
(b) Produce lipids with hydrocarbon tails that are shorter and have more double
bonds.
(c) Decrease the amount of cholesterol in the membrane.
(d) Decrease the amount of glycolipids in the membrane. - ANS - B
\11-12 Some lipases are able to cleave the covalent bonds between the glycerol
backbone and the attached fatty acid. What final products do you expect to
accumulate through the action of the enzyme monoacylglycerol lipase?
(a) phosphoglycerol and free fatty acid
(b) sterol and glycerol
(c) free phosphate and glycerol
(d) glycerol and free fatty acid - ANS - D
\11-13 Which of the following phospholipid precursors is the most hydrophobic?
(a) triacylglycerol
(b) diacylglycerol
(c) phosphate
(d) glycerol - ANS - A
\11-14 Three phospholipids X, Y, and Z are distributed in the plasma membrane as
indicated in Figure Q11-14. For which of these phospholipids does a flippase
probably exist?
(a) X only
(b) Z only
(c) X and Y
(d) Y and Z - ANS - C
\11-15 Where does most new membrane synthesis take place in a eukaryotic cell?
(a) in the Golgi apparatus
(b) in the endoplasmic reticulum
(c) in the plasma membrane
(d) in the mitochondria
(e) on ribosomes - ANS - B
\11-16 Water molecules readily form hydrogen bonds with other polar molecules,
and when they encounter nonpolar molecules they must form hydrogen-bonding
networks with neighboring water molecules. Which of the following molecules
will cause a "cage" of water to form?
