Download Exam 2 Review - Iowa State University

Exam 2 Review
Supplemental Instruction
Iowa State University
According to the second law of thermodynamics,
a) energy cannot be created or destroyed.
b) each energy transfer decreases the disorder of
a system.
c) energy is constant in the universe.
d) each energy transfer increases the level of
disorder in a system.
2. Reactions that release free energy are,
a) Spontaneous.
b) Endergonic.
c) Exergonic.
d) Endothermic.
e) both a and b.
3. Enzymes speed up reactions by
a) providing chemical energy to fuel a reaction.
b) lowering the activation energy necessary to
initiate the reaction.
c) causing an endergonic reaction to become an
exergonic reaction.
d) substituting for one of the reactants necessary
for the reaction.
4. Competitive inhibitors,
a) lowers the Km only.
b) lowers the Km and lowers the V max.
c) raises the Km only.
d) raises the Km and raises the V max.
e) raises the Km and lowers the V max.
5. Which of the following processes require energy?
a) creating ion gradients across membranes.
b) muscle shortening.
c) protein synthesis.
d) All of the above.
6. The process of muscle shortening requires
a) synthetic work.
b) mechanical work.
c) electrical work.
d) concentration work.
7. Heat is an example of
a) potential energy.
b) electrical energy.
c) kinetic energy.
8. Enzymes
a) are biological catalysts, highly specific for
their substrates.
b) change reactants into products through
transition state intermediates
c) are not consumed in the reaction.
d) All the above.
9. Enzymes are always proteins.
a) True
b) false
10. In competitive inhibition,
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Kali Disterhoft
BIOL 212 (2)
Dr.Kukday
10/6/14
a) the inhibitor competes with the normal
substrate for binding to the enzymes active
site.
b) an inhibitor permanently inactivates the
enzyme by combining with 1 of its
functional groups.
c) the inhibitor binds with the enzyme at a site
other than the active site.
Which is an example of how metabolic pathways
are regulated?
a) gene regulation.
b) biochemical regulation.
c) cellular regulation.
d) feedback inhibition.
e) all the above.
According to the second law of thermodynamics,
which of the following statements is
INCORRECT?
a) a. The synthesis of large molecules from small
molecules is exergonic (releases free
energy).
b) Living organisms cannot be closed system.
c) Life exists at the expense of energy derived
from its environment.
d) A living cell can never function indefinitely
as a closed system.
e) Every chemical reaction in a cell results in a
loss of free energy.
ATP is produced by _______ , ________
reactions and is used to drive ________,
________ reactions. What words filled in these
four spaces (in order) result in a true statement?
a) endergonic, catabolic exergonic, anabolic
b) exergonic, anabolic endergonic, catabolic,
c) exergonic, catabolic endergonic, anabolic
d) endergonic, anabolic exergonic, catabolic
Why is ATP an important molecule in
metabolism?
a) Its hydrolysis provides an input of free energy
for exergonic reactions.
b) It provides energy coupling between
exergonic and endergonic reactions.
c) Its terminal phosphate group is highly
unstable, and thus reactive.
What is the term that best describes the metabolic
pathway in which glucose (C6H12O6) is
degraded to carbon dioxide (CO2) and water?
a) cellular respiration
b) glycolysis
c) fermentation
d) citric acid cycle
e) oxidative phosphorylation
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16. What molecule is produced by glycolysis, and is
then imported into the mitochondria to enter into
the TCA cycle?
a) Glucose
b) NADPH
c) Pyruvate
d) citric acid
17. A proton ionophore is a substance that creates a
proton leak in a membrane. What might you
predict that a proton ionophore would do in
mitochondria?
a) Nothing.
b) Create a greater proton motive force.
c) Block electrons from being transported from
one carrier to another.
d) Prevent the synthesis of ATP.
e) None of the above.
18. A substance that increases the number of protons
(H+) in the mitochondrial matrix (and has no
other effect on the cell) would theoretically ____.
a) increase the ATP yield of glycolysis
b) decrease ATP yield in the citric acid
cycle/Krebs cycle
c) inhibit pyruvate metabolism
d) decrease the ATP yield in oxidative
phosphorylation
19. Which of the following statements concerning the
metabolic degradation of glucose (C6H12O6) to
carbon dioxide (CO2) and water is (are) true?
a) The breakdown of glucose to carbon dioxide
and water is exergonic, releasing free
energy.
b) The breakdown of glucose to carbon dioxide
and water in a cell is usually coupled to the
production of more than 25 ATP.
c) The breakdown of glucose to carbon dioxide
and water is completed in the reactions of
the citric acid cycle in the mitochondrial
matrix.
d) All of the above are true.
20. The citric acid cycle is a “cycle” because:
a) CO2 is released at various steps in the cycle
and then fixed again.
b) oxaloacetate is regenerated in each round of
the cycle.
c) ATP is hydrolyzed, then resynthesized.
d) All of the above.
e) None of the above.
21. Lactate acidosis occurs when
a) There is too much lactate and pyruvate in the
blood.
b) There is too little lactate and pyruvate in the
blood.
22. In anaerobic respiration
a) NADH is oxidized to NAD+
b) FADH2 is oxidized to FADH+
c) NAD+ is reduced to NADH
d) FADH+ is reduced to FADH2
23. In the light reactions of photosynthesis
a) NADPH is oxidized from NADP
b) NADP is reduced to NADPH
24. During the first phase of the Calvin cycle, CO2 is
incorporated into ribulose bisphosphate by
a) Oxaloacetate.
b) Rubisco.
c) RuBP.
d) Quinone.
e) G3P.
25. Which statement is NOT TRUE about
glycolysis? If all are true, select alternative D.
a) Two ATP are needed per glucose in the
energy investment phase of glycolysis
b) Four ATP per glucose are produced during the
energy yielding phase of glycolysis
c) The two NADH produced per glucose can be
oxidized back to NAD+ by the
mitochondrial electron transport chain.
d) All of the above are true.
26. Where does the Calvin cycle take place?
a) stroma of the chloroplast
b) thylakoid membrane
c) cytoplasm surrounding the chloroplast
d) chlorophyll molecule
e) outer membrane of the chloroplast
27. How many carbon atoms are fed into the citric
acid cycle as a result of the oxidation of one
molecule of pyruvate, and eventually emerge as
CO2?
a) 2
b) 4
c) 6
d) 8
28. In DNA, hydrogen bonding occurs
a) Between the sugars of each nucleotide.
b) Between the nitrogenous bases.
c) Between the phosphate group of one
nucleotide and the hydroxyl group of
another.
29. DNA replication occurs during what stage of the
cell cycle?
a) G1 phase.
b) Prophase
c) S phase
d) Metaphase
30.In what direction is DNA replicated?
a) 5’ -> 3’
b) 5’ <- 3”
31.What enzyme removes the first primer and replaces
it with DNA?
a) DNA polymerase II
b) DNA primase
c) DNA polymerase I
d) DNA ligase
32.The structural feature that allows near-perfect
copying of DNA molecules is
a) their sugar-phosphate backbone.
b) the capability of its nitrogenous bases to
form specific hydrogen bonds that lead to
matching of specific pairs of nucleotides.
c) disulfide bonds that hold the two helixes
together.
d) the three-component (base, sugar, and
phosphate) structure of the nucleotides,
because all three must be matched to make a
perfect copy.
33.What is the function of topoisomerase during DNA
replication?
a) It separates the two strands of the double
helix.
b) It relieves the overwinding of DNA ahead of
the replication fork due to DNA strand
separation.
c)
It synthesizes the RNA primers used to
initiate DNA replication.
d) It joins the Okazaki fragments together.
34.Which of the following statements about DNA
replication is NOT correct?
a) Leading strand synthesis is continuous,
while lagging strand synthesis is
discontinuous.
b) Both leading and lagging strands are
synthesized in the 5’ to 3’ direction.
c) Leading strand synthesis is conservative,
while lagging strand synthesis is semiconservative.
d) Completion of the lagging strand requires
ligation of Okazaki fragments
35.What are the repeating DNA sequences at the ends
of chromosomes that protect them from loss of
important DNA during replication?
a) Telomeres
b) Telomerase
c) Replicons
d) Primers
e) Promoters
36.The following statements are consistent with the
central dogma –
a) During transcription, DNA is copied into
RNA.
b)
During translation, RNA sequences code for
polypeptide sequences.
c) The process of transcription produces a
polypeptide sequence.
d) DNA is translated into ribonucleotides.
e) A and B.
37.A DNA strand in double-stranded DNA is based
paired with its complementary strand. The strand
complementary to a strand with the sequence 5’GCAAGTCATGCCGAAT-3’ would read as follows:
a) 5’-CGTTCAGTACGGCTTA-3’
b) 5’-ATTCGGCATGACTTGC-3’
c) 5’- GCAAGTCATGCCGAAT-3’
d) 5’-ATGCAGTTACAATGCA-3’
38.Which of the following may be involved in
combinatorial control of eukaryotic gene expression
a) Activator proteins
b) Repressor proteins
c) DNA methylation
d) Alteration of chromatin structure
e) All of the above
39.In bacterial and eukaryotic cells, gene regulation
occurs most commonly
a) During translation.
b) During transcription.
c) During RNA processing.
d) During post-translation.
40.What would occur if the TATA box was mutated?
a) Transcription would not happen.
b) Translation would not happen.
c) Transcription would still occur.
d) Translation would still occur.