Download 03_Clicker_Questions

Chapter 3
The Molecules of Life
Clicker Questions for use with Classroom Response Systems
Campbell Essential Biology, Fourth Edition
– Simon, Reece, and Dickey
Campbell Essential Biology with Physiology, Third Edition
– Simon, Reece, and Dickey
Questions prepared by Brad Williamson, updated by Mike Tveten
© 2010 Pearson Education, Inc.
Concept Check
This lysozyme protein molecule is
found in tears and protects the eye
from bacterial infections. Which of
the following best describes the
outside of the molecule?
a. Mostly hydrophobic side groups
are on the surface of the
molecule.
b. Mostly hydrophilic side groups
are on the surface of the
molecule.
c. The side groups on the exterior
of the molecule are mostly
nonpolar.
d. The side groups on the exterior
are constantly changing
between nonpolar and polar as
the protein chain bends and
folds.
© 2010 Pearson Education, Inc.
Concept Check
When proteins are heated, they
usually denature. If moderate heat
were applied to this molecule of
DNA, what part of the molecule
would break down or break apart
first? Use your knowledge of
chemical bonds.
a. The nucleotides along each side
would break apart.
b. The sugar-phosphate backbone
would separate from the
nitrogen bases.
c. The nitrogen base pairs would
separate in the interior of the
molecule.
© 2010 Pearson Education, Inc.
Interpreting Data
The amino acid side groups interact to create the threedimensional structures of proteins. Some amino acids have
hydrophilic side groups, whereas others have hydrophobic side
groups. Of the hydrophilic groups, some are acids and others
are bases.
Acid side groups end with a carboxyl group.
Basic side groups end with an amine group.
© 2010 Pearson Education, Inc.
Interpreting Data
The key to a protein’s function is its shape. The shape can be
altered (or denatured) under unfavorable conditions. The pH of
the solution is an important factor in determining protein shape.
Depending on the pH of the solution, carboxyl groups and amine
groups may or may not be charged.
-COOH
-COO-
-NH2
- NH3+
© 2010 Pearson Education, Inc.
Interpreting Data
This graph indicates how the charge on an amino acid “R” group
can be determined by the pH of the solution. The green line
across the middle of the graph represents the neutral pH of most
cells.
At neutral pH (7), which of the following amino acids carries a
charge?
a. aspartic acid
b. glutamic acid
c. lysine
d. all of the above
© 2010 Pearson Education, Inc.
Interpreting Data
At an acidic pH of 3, which of the following amino acids carries
a charge?
a. aspartic acid
b. glutamic acid
c. lysine
d. all of the above
© 2010 Pearson Education, Inc.
Interpreting Data
At a basic pH of 12, which of the following amino acids carries a
charge?
a. aspartic acid
b. glutamic acid
c. lysine
d. both a and b
© 2010 Pearson Education, Inc.
Biology and Society
Looking for additional competitive advantage, some athletes have
turned to anabolic steroids to enhance their performance. Due in
part to the downsides of steroid use, most sports organizations
ban the use of steroids. This controversy has played a large role
in the Olympics. Do you agree that organizations such as the
IOC should ban the use of performance-enhancing drugs?
Strongly
Agree
A.
© 2010 Pearson Education, Inc.
B.
C.
D.
E.
Strongly
Disagree
Biology and Society
Olympic track and field records appear to have leveled off and
perhaps even declined from the early to mid 1990s. Some have
suggested that many of the records set during this time period
were due to drug-based enhancement.
Should these records be expunged?
Strongly
Agree
A.
© 2010 Pearson Education, Inc.
B.
C.
D.
E.
Strongly
Disagree
Biology and Society
Personal responsibility is a vital component of a free society.
Some feel that use of drugs such as anabolic steroids should be a
matter of personal choice. Others disagree. Are regulations
controlling the use of anabolic steroids properly applied?
Strongly
Agree
A.
© 2010 Pearson Education, Inc.
B.
C.
D.
E.
Strongly
Disagree