Chemistry C483 Biological Chemistry
Fall 2008
Exam #3
December 2, 2008
Specific metabolic pathways can be found on page 15 & 16. You may tear
this page free. Page 14 is blank and may be used as scratch paper.
Name_____________________________________________________
C483 Fall 2008 Exam 3 Page 2
Exam points
1. _________________/13 pts
2. _________________/ 9 pts
3. _________________/ 8 pts
4. _________________/ 16 pts
5. _________________/ 6 pts
6. _________________/ 9 pts
7. _________________/ 12 pts
8. _________________/ 9 pts
9. _________________/ 3 pts
10._________________/ 15 pts
Extra. ______________/2 pts
Total_______________________/100pts
C483 Fall 2008 Exam 3 Page 3
1. (13 pts) Which of the ten enzymes of glycolysis are being described? For some statements, more
than one enzyme may fit the description: You must include all that apply to receive credit for the
answer. Including incorrect answers will lead to no credit for that description. You may use an
enzyme more than once.
a. Catalyzes a regulated reaction
b. Catalyzes a reaction that requires ATP
c. Catalyzes a reaction that produces ATP
d. Catalyzes a reaction that produces
NADH
e. Inhibition of this enzyme would result in
the NET yield of 1 NADH and a NET loss
of 2 ATP, instead of the normal
glycolytic yield.
f. Catalyzes a lyase reaction
g. Catalyzes a transferase reaction
h. Catalyzes the phosphorylation of its
substrate
a. ___________________________
b. ___________________________
c. ___________________________
d. ___________________________
e. ___________________________
f. ___________________________
g. ___________________________
h. ___________________________
C483 Fall 2008 Exam 3 Page 4
i. Fructose 2,6-bisphosphate is an
allosteric activator of this enzyme
j. These enzymes catalyze reactions with
a ∆G close to, or equal to, zero
k. These enzymes are bypassed in
gluconeogenesis
l. A product of this enzyme is
2-phosphoglycerate
m. Catalyzes an isomerase reaction
i. __________________________
j. ___________________________
k. ___________________________
l. ___________________________
m. ___________________________
C483 Fall 2008 Exam 3 Page 5
2. (9 pts) Indicate if the following statements describe an anabolic pathway (synthesis), a catabolic
pathway (degradation), or both. You may use an answer more than once.
a. Glycolysis
b. Gluconeogenesis
c. Results in a NET loss of energy
d. Overall, the process is reductive
e. Products of this process converge
f. This type of pathway leads to the
production of reduced cofactors (NADH,
FADH2)
g. β-oxidation
h. Glycogen metabolism
i. Pentose phosphate pathway
a. ___________________________
b. ___________________________
c. ___________________________
d. ___________________________
e. ___________________________
f. ___________________________
g. ___________________________
h. ___________________________
i. ___________________________
C483 Fall 2008 Exam 3 Page 6
3. (8 pts) For the following statements, indicate which of the nine coenzymes initially discussed in
class (ATP, NAD+, NADP
+, FMN, FAD, CoA, TPP, THF, or lipoamide) fit the description. For some
statements, more than one coenzyme may fit the description: You must include all that apply to
receive credit for the answer. Including incorrect answers will lead to no credit for that description.
You may use a coenzyme more than once. (If you need complete names of the coenzymes, you can
find them on page 16).
a. Transfers an acyl group
b. Contains an AMP moiety
c. Transfers C1 units
d. Involved in oxidation/reduction
reactions
e. Accepts and donates electrons one at a
time
f. May be involved in the following
reaction:
g. Works with kinases
h. A prosthetic group
a. ___________________________
b. ___________________________
c. ___________________________
d. ___________________________
e. ___________________________
f. ___________________________
g. ___________________________
h. ___________________________
C483 Fall 2008 Exam #1 Page 7
4. (16 pts) The major source of cellular energy is adenosine triphosphate (ATP).
a. Draw the structure of ATP. Include Mg2+
in your structure in one of the two correct
locations.
b. Circle all the atoms present in the phosphoryl group which is transferred by ATP during a
kinase reaction.
c. Give 2 reasons why the phosphoanhydride bond of ATP is a high energy bond.
d. What is the energy, in kJ/mol, released from hydrolysis of 1 mol ATP to ADP + Pi?
C483 Fall 2008 Exam #1
5. (6 pts) A common coenzyme in metabolism is NAD
a. NAD+ accepts a hydride ion. What is a hydride ion?
b. In the molecule below
A common coenzyme in metabolism is NAD+.
accepts a hydride ion. What is a hydride ion?
In the molecule below, circle the atom (or atoms) that accepts the hydride ion.
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the hydride ion.
C483 Fall 2008 Exam #1
6. (9 pts) Pentose Phosphate Pathway
a. Using the reaction numbers indicted in the
the reactions that will occur if the cell needs to produce
b. Using the reaction numbers indicted in the diagram above indicate, in the correct order,
the reactions that will occur if the cell needs to produce
c. Using the reaction numbers indicted in the diagram above indicat
the reactions that will occur if the cell needs to produce
Pentose Phosphate Pathway
reaction numbers indicted in the diagram above indicate, in
the reactions that will occur if the cell needs to produce only NADPH.
Using the reaction numbers indicted in the diagram above indicate, in the correct order,
the reactions that will occur if the cell needs to produce only ribose-5-
Using the reaction numbers indicted in the diagram above indicate, in the correct order,
the reactions that will occur if the cell needs to produce only ATP.
Page 9
indicate, in the correct order,
Using the reaction numbers indicted in the diagram above indicate, in the correct order,
-phosphate.
e, in the correct order,
C483 Fall 2008 Exam #1 Page 10
7. (12 pts) Indicate if the following will increase, decrease, or remain unaffected if glucose levels
are high.
a. Glycolysis
b. Pyruvate dehydrogenase
c. The citric acid cycle
d. Oxidative phosphorylation
e. Gluconeogenesis
f. Glycogen synthesis
g. Glycogen degradation
h. Triacylglyceride synthesis
i. Triacylglyceride
degradation
j. Insulin levels
k. Glucagon levels
l. Epinephrine levels
a. ___________________________
b. ___________________________
c. ___________________________
d. ___________________________
e. ___________________________
f. ___________________________
g. ___________________________
h. ___________________________
i. ___________________________
j. ___________________________
k. ___________________________
l. ___________________________
C483 Fall 2008 Exam #1 Page 11
8. (9 pts) The fatty acid arachidate (20:0) is degraded by ββββ-oxidation (the ββββ-oxdation pathway is
provided on page 15).
a. How many rounds of β-oxidation will it undergo?
b. How much ATP is generated from the complete oxidation of arachidate? (Show your
work).
C483 Fall 2008 Exam #1 Page 12
9. (3 pts). What is the role of cytochrome c in oxidative phosphorylation?
10. (15 pts). You must answer 5 of the following 6 questions (a-f). Please keep your answers succinct,
but complete. If you answer more than 5, we will only grade the first 5.
a. A mutase is an isomerase enzyme. What is unique about a mutase?
b. Under anaerobic conditions, what two molecules can pyruvate be converted to?
c. What is the purpose of the Cori Cycle?
C483 Fall 2008 Exam #1 Page 13
d. When processed through glycolysis, why is more energy produced from a
monosaccharide released from a linear portion of glycogen instead of one released from
a branching point?
e. What molecule is pyruvate converted to by the enzyme pyruvate dehydrogenase?
f. Why does oxidation of NADH to NAD+ result in 1 more ATP than oxidation of FADH2 to
FAD?
Extra Credit (2 pts). Fill in the blank:
To show why metabolism occurs in discreet steps instead of one combustion reaction, we
watched a video where a ________________ was ignited.
C483 Fall 2008 Exam #1
You may find the following information helpful as you take this exam:You may find the following information helpful as you take this exam:
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C483 Fall 2008 Exam #1
Full names of the coenzymes mentioned in question 3:
Adenosine triphosphate (ATP), Nicotinamide adenine dinucleotide
dinucleotide phosphate (NADPH),
Coenzyme A (CoA), thiamine pyrophosphate
Full names of the coenzymes mentioned in question 3:
Nicotinamide adenine dinucleotide (NAD+), nicotinamide adenine
(NADPH), flavin mononucleoside (FMN), flavin adenine dinucleotide
thiamine pyrophosphate (TPP), Tehtrahydrofolate (THF).
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nicotinamide adenine
flavin adenine dinucleotide (FAD),