Transcript Chapter 2

Active Lecture Questions for
BIOLOGY, Eighth Edition
Neil Campbell & Jane Reece
Chapter 7
Membrane Structure and Function
Questions prepared by
Jung Choi,
Georgia Institute of Technology
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.
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
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.
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.
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.
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
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.
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
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.
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+
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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.
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.
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
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.
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
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.
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
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings.