BIOCHEMISTRY
EXAM
Energy Metabolism
Name____________________
I.D. _____________________
COOH- C OH
HO C-H
Questions pertains to the figure:
D
E
H- C OH
+ CO2
H- C-OH
Glucose-6phosphatase
A
CH2OH
CH2OPO3=
O OH
C
H
H OH
c. D-glucose
HN
O
OH H
O
d. UDP-glucose
O
N
O P O P O CH2
HO
O
H OH
O
O
HO
CH2OPO3
C= O
HO-C-H
H-C-OH
F
H-C-OH
CH2OPO3
B
1. In the above figure compound A is:
a. Glucose-6-PO4
b. Fructose-6-PO4
O
H
OH H
HO
O
CH2OH
OH
6-phosphogluconate
2.
a.
b.
The enzyme labeled F is:
Hexokinase
Glucose-6-PO4 dehydrogenase
c. phosphofructokinase-1
d. aldolase
e. phosphoglucomutase
3.
a.
b.
Compound D is:
6-phosphogluconate
6-phosphoglucono--lactone
c. glucose-1-PO4
d. fructose-6-PO4
e. ribose-5-PO4
4.
a.
b.
Compound B is:
6-phosphogluconate
6-phosphoglucono--lactone
c. fructose-6-PO4
d. glucose-1-PO4
e. ribose-5-PO4
5. Compound C is:
a. 6-phosphogluconate
b. 6-phosphoglucono--lactone
c. fructose-6-PO4
d. glucose-1-PO4
e. ribose-5-PO4
6.
a.
b.
Compound E is:
sedoheptulose-7-PO4
glyceraldehyde-3-PO4
c. ribulose-5-PO4
d. xyulose-5-PO4
e. ribose-5-PO4
7.
a.
b.
The cofactor biocytin is used in which of the following reactions?
the conversion of pyruvate to OAA
c. the conversion of OAA to PEP
the conversion of PEP to pyruvate
d. the phosphorylation of D-glucose
e. the hydrolysis of
glucose-6-PO4
8. In the previous question 3 of the 5 reactions mentioned occur in gluconeogenesis. These are:
a. a, b, d
b. b,c,e
c. a, c, d
d. b, c, d
e. a, c, e
9.
a.
b.
c.
Which glycolytic reaction is NOT reversible under physiological conditions?
the conversion of pyruvate to lactate
d. the conversion of ribulose-5-PO4 to xyulose-5-PO4
the conversion of PEP to 2-phosphoglycerate
e. none of these reactions is reversible
the conversion of fructose-6-PO4 to fructose-1,6-bisPO4
10. Asked to name 6 major glycolysis intermediates on an exam, a student put down: glucose-1,6-bisphosphate,
fructose-3,6-bisphosphate, 1,3 bisphosphate glycerate, 1-phosphoglycerate, pyruvate, and phosphoenolpyruvate. How
would you score the student’s RIGHT answers?
a. 2 out of 6
b. 3 out of 6
c. 4 out of 6
d. zero out of 6
e. 6 out of 6
11. Another student was asked to name 6 enzymes in the gluconeogenic pathway starting with lactate: The answers were:
a. Lactate dehydrogenase
b. Aldolase
c. PEP carboxykinase
d. Fructose 1,6 bisphosphatase
e. Malate dehydrogenase
f. Pyruvate carboxylase
How would you score the right answers?
a. 2 out of 6
b. 3 out of 6
c. 4 out of 6
d. 5 out of 6
e. 6 out of 6
12.
a.
b.
c.
d.
e.
Were he alive today and allowed to lecture on the topic of making a superior wine, Louis Pasteur would warn against:
microbial organisms that can infect the grapes
oxygen that can cut down the yield of ethanol
sunlight that could over expose the grapes and accelerate the ripening
rainfall, and the possibility that the grapes would imbibe too much water
Dolly Madison, who believed that grape juice rather than wine should be served out all White House functions, and
thus inspired Welch to establish his company.
13.
a.
b.
c.
d.
e.
Were he alive today, Hans Krebs would remind you in very forceful terms that:
citric acid is a tricarboxylic acid
succinate must be oxidized by an enzyme that requires FAD as a coenzyme
the cycle reactions both end and start with oxaloacetate
two carbon dioxide molecules are lost from the citrate molecule during one turn of the cycle
all of the above
14.
a.
b.
c.
d.
e.
If you were asked to describe a similarity in the structures of L-malate and the amino acid L-serine, you would say:
both contain an –NH3 group
both contain a single carboxyl group that behaves as a strong acid
both contain a single –OH group
both are found in the Krebs cycle
both have an aromatic ring in their structure
15.
a.
b.
c.
d.
e.
If your were asked to describe a structural similarity between glutathione and cysteine, you would say:
both have a sulfhydryl (-SH) group
both have an acetate group
both have a heme group
both are peptides
both have carbonyl groups that bind phosphate
16. In what pathway would you find the enzyme galactose-1-PO4 uridylyl transferase?
a. glycogen synthesis
c. glycogen breakdown
e. galactose degradation
b. pentose phosphate
d. fructose degradation
17. In what pathway would you find the enzyme amylo(1,41,6)-transglycosylase:
a. glycogen breakdown
c. galactose degradation
e. the pentose phosphate pathway
b. glycogen synthesis
d. fructose degradation
18. In what pathway would you find the enzyme amylo-1,6-glucosidase:
a. glycogen breakdown
c. galactose degradation
b. glycogen synthesis
d. fructose degradation
e. the pentose phosphate pathway
19. To convert phosphorylase a into phosphorylase b requires the enzyme _____ and uses ______.
a. phosphorylase a kinase, ATP
c. phosphorylase a phosphatase, H2O
e. phosphorylase, ADP
b. phosphorylase a phosphatase, ATP
d. phosphorylase b phosphatase, H2O
20. When glycogen synthase I is converted into glycogen synthase D, the enzyme becomes sensitive to:
a. D-glucose
c. D-amino acids
e. glucose-6-PO4
b. ADP
d. D-fructose
Questions 21-28 pertain to the figure shown below: Boxes touching the apexes are unnamed intermediates.
CH3 C S-CoA
O
A
Citrate
OAA
Isocitrate
CO2
D
-Kg
B
CO2
Fumarate
Succinate
C
21. In the figure compound A is:
a. D-glucose
b. L-lactate
c. L-alanine
d. pyruvate
e. PEP
22. In the figure compound B is:
a. cis-aconitate b. L-aspartate c. L-glutamate
d. L-lactate
e. PEP
23. In the figure compound C is:
a. L-malate
b. NADH
c. dihydrolipoate
d. acetyl-CoA
e. succinyl-CoA
24. In the figure compound D is:
a. L-malate
b. NADH
c. dihydrolipoate
d. acetyl-CoA
e. succinyl-CoA
25. When citrate is oxidized to OAA, how many molecules of NADPH are synthesized? (careful)
a. none
b. one
c. two
d. three
e. four
26. When citrate is oxidized to OAA, how many molecules of ATP energy are generated?
a. 6
b. 12
c. 18
d. 24
e. 36
27. When citrate is oxidized completely to CO2 and H2O, how many molecules of ATP energy are generated?
a. 6
b. 12
c. 18
d. 24
e. 36
28. This compound is a substrate for the enzyme dihydrolipoyl transacetylase. Name the compound.
a. isocitrate
b. -ketoglutarate
c. succinyl-CoA
d. succinate
e. HS-CoA