Download CH 7 CQ

CLICKER QUESTIONS
For CAMPBELL BIOLOGY, NINTH EDITION
Jane B. Reece, Lisa A. Urry, Michael L. Cain, Steven A. Wasserman, Peter V. Minorsky, Robert B. Jackson
Chapter 7
Membrane Structure and
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Questions prepared by
Jung Choi
Georgia Institute of Technology
© 2011 Pearson Education, Inc.
Membrane Structure
Which of the following best describes the structure of a biological
membrane?
a)
two layers of phospholipids with proteins embedded between the two
layers
b)
a mixture of covalently linked phospholipids and proteins that
determines which solutes can cross the membrane and which cannot
c)
two layers of phospholipids with proteins either crossing the layers or
on the surface of the layers
d)
a fluid structure in which phospholipids and proteins move freely
between sides of the membrane
e)
two layers of phospholipids (with opposite orientations of the
phospholipids in each layer) with each layer covered on the outside
with proteins
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Osmosis
Which of the following statements about osmosis is correct?
a) If a cell is placed in an isotonic solution, more water will
enter the cell than leaves the cell.
b) Osmotic movement of water into a cell would likely occur if
the cell accumulates water from its environment.
c) The presence of aquaporins (proteins that form water
channels in the membrane) should speed up the process
of osmosis.
d) If a solution outside the cell is hypertonic compared to the
cytoplasm, water will move into the cell by osmosis.
e) Osmosis is the diffusion of water from a region of lower
water concentration to a region of higher water
concentration.
© 2011 Pearson Education, Inc.
Membrane Lipids and Fluidity
An animal cell membrane will be more fluid at
room temperature if it contains
a) more cholesterol.
b) longer chain fatty acids.
c) more cis-unsaturated and polyunsaturated fatty
acids.
d) more trans-unsaturated fatty acids.
e) any of the above
© 2011 Pearson Education, Inc.
Lipid Rafts, Cholesterol, and Membrane Fluidity
Regions of the plasma membrane called “lipid
rafts” have high concentrations of cholesterol.
Consequently, the proteins in lipid rafts
a) diffuse more freely in the membrane.
b) tend to stay clustered together.
c) are able to flip across the lipid bilayer from inside to
outside and vice versa.
d) cannot function as receptors.
e) cannot undergo endocytosis.
© 2011 Pearson Education, Inc.
Transmembrane Domains
Which of the following amino acids would most
likely be present in the transmembrane domain
of an integral membrane protein?
a) a charged amino acid like lysine
b) a polar amino acid like serine
c) a special amino acid like glycine or proline
d) a hydrophobic amino acid like valine
e) any of the above, with no preference
© 2011 Pearson Education, Inc.
Membrane Synthesis and Sidedness
An oligosaccharide covalently linked to a lipid
in the lumen of the rough ER may end up on
the
a) cytoplasmic face of the plasma membrane.
b) extracellular face of the plasma membrane.
c) cytoplasmic face of a secretory vesicle.
d) any of the above
© 2011 Pearson Education, Inc.
Membrane Permeability
Which of the following molecules will diffuse
most quickly across a lipid bilayer membrane?
a) H2O
b) O2
c) H2PO4–
d) glucose
e) Na+
© 2011 Pearson Education, Inc.
Osmosis
If a marine algal cell is suddenly transferred
from seawater to freshwater, the algal cell will
initially
a) lose water and decrease in volume.
b) stay the same: neither absorb nor lose water.
c) absorb water and increase in volume.
© 2011 Pearson Education, Inc.
Transport Kinetics: Passive Diffusion
Which of the curves below illustrates uptake of
nitrous oxide into the cell, if nitrous oxide
diffuses passively across the membrane?
a) A
b) B
c) C
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Transport Kinetics: Passive Diffusion
Which of the curves below illustrates uptake of
lactose into the cell via a passive transporter?
a) A
b) B
c) C
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Transport Kinetics: Passive Diffusion
Which of the curves below illustrates uptake of
phosphate into the cell by an active transport
system?
a) A
b) B
c) C
© 2011 Pearson Education, Inc.