Transcript Review session for exam-I

Review session for exam-I
Lectures 1-5
Q1. Carbohydrates are
a)
b)
c)
d)
e)
polyhydroxy aldehydes.
polyhydroxy ketones.
polyhydroxy acids.
polyhydroxy alcohols.
a and b.
Q2. The simplest
carbohydrates are
a)
b)
c)
d)
D- and L-glyceraldehyde.
dihydroxyacetone and glycerate.
All of the above.
None of the above.
Q3. An aldehyde and an alcohol
can react to form a
a)
b)
c)
d)
e)
hemiaketal.
hemiketal.
hemiacetal.
All of the above.
None of the above.
Q4. Sugars are commonly linked
to which amino acid residues
in glycoproteins?
a)
b)
c)
d)
e)
tyrosine and asparagine
serine, threonine, and asparagine
serine, tyrosine, and asparagine
serine and threonine
a and d
Q5. Draw the Fischer
projection structures of
glucose.
Q6. Identify the monosaccharides
involved and the type of
linkage in lactose?
Q7. What is the standard-state
free energy (ΔG°′) for the
hydrolysis of ATP to ADP?
a)
b)
c)
d)
e)
+45.6 kJ/mol.
45.6 kJ/mol.
-30.5 kJ/mol.(-7.3 kcal/mol)
-15.6 kJ/mol.
+30.5 kJ/mol.
Q8. Reaction pathways that
transform fuels into
cellular energy are
a)
b)
c)
d)
e)
anabolic
catabolic
allobolic
All of the above.
None of the above.
Q9. Which of the following
molecule(s) have a higher
phosphoryl-transfer
potential than ATP?
a)
phosphoenolpyruvate
b)
creatine phosphate
c)
1,3-bisphosphoglycerate
d)
a and b
e)
a, b, and c
Q10. The reduced form of flavin
adenine dinucleotide is
a)
b)
c)
d)
e)
FADH.
FAD.
FADH2+.
FADH2.
None of the above.
Q11. What two 3-carbon molecules
are generated by the cleavage
of fructose-1,6-bisphosphate?
a)
glyceraldehyde-3-phosphate and 3phosphoglycerate
b)
glyceraldehyde-3-phosphate and
dihydroxyacetone phosphate
c)
pyruvate and phosphoenolpyruvate
d)
enolase and 2-phosphoglycerate
e)
glyceraldehyde-3-phosphate and pyruvate
Q12. What is the function of
glyceraldehyde 3-phosphate
dehydrogenase?
a)
oxidation by NAD+ and formation of acylphosphate
b)
oxidation of the alcohol to an aldehyde
c)
dehydration and dephosphorylation of
GAP
d)
hydrolysis of GAP
e)
None of the above.
Q13. What is substrate level
phosphorylation?
a)
phosphorylation of AMP by ATP
b)
ATP synthesis when the phosphate donor is a
substrate with high phosphoryl transfer potential
c)
phosphorylation of glycolytic intermediates
d)
phosphorylation of ATP coupled to an ion gradient
e)
ATP and AMP synthesis from two molecules of ADP
Q14. Which of the following is
an example of an
oxidation reaction?
a)
b)
c)
.
.
.
-
O2C
CH2 CH2 CO2
CO2C C
+ FADH2
O2C
H
H
+ FAD
O
O
CH3CCO2-
-
O2CCH2CCO2- + ADP + Pi
+ CO2 + ATP
CO2-
CO2H2N C H
H C NH2
CH3
CH3
d)
Ala-Ser + H2O → Ala + Ser
e)
None of the above.
Q15. What are the primary
metabolic fates of pyruvate?
a)
b)
c)
d)
e)
ethanol
lactate
acetyl CoA
All of the above.
None of the above.
Q16. Lactose intolerance is
caused by a deficiency of
a)
b)
c)
d)
e)
lactase
elastase
lactose
sucrase
None of the above.
Q17. Both hexokinase and glucokinase
phosphorylate glucose.
The function of glucokinase is to
phosphorylate glucose in liver cells as
a means to regulate blood-sugar
levels.
Would you expect its Km to be higher
or lower than hexokinase?
Q18. What is the biochemical explanation for
galactosemia?
Q19. Starting with Fructose 1,6 –Bisphosphate,
how many ATP’s are made until the
production of pyruvate?
Q20. For each molecule of glucose converted
to pyruvate in the glycolytic pathway, ___
molecules of ATP are used initially
(Phase I) and ____ molecules of ATP are
produced (Phase II) for an overall yield of
___ molecules of ATP/glucose.
The "ATP math" is:
a)
b)
c)
d)
e)
2+4=2
1+4=3
-2 + 5 = 3
-1 + 2 = 1
2+2=4
Q21. Glycolysis in the
erythrocyte produces
pyruvate that is further
metabolized to:
Q22. An enzyme in glycolysis that
catalyzes a reversible
reaction and generates a
high-energy bond is
a) Hexokinase
b) Pyruvate
c)
kinase
Phosphofructokinase
d) Glyceraldehyde
3-phosphate dehydrogenase
Q23. After complete metabolism of one
molecule of glucose to carbon
dioxide via the TCA cycle, what will
be the net change in the amount of
oxaloacetate in the mitochondrion?
a)
b)
c)
d)
e)
Increased by two molecules
Increased by one molecule
Unchanged
Decreased by one molecule
Decreased by two molecules
Q24. An abnormal accumulation
of galactose 1-P in the liver
would be caused by the
deficiency of
a)
glucose 6-phosphate dehydrogenase.
b)
glucose 6-phosphatase.
c)
galactokinase.
d)
galactose 1-phosphate uridylyl transferase.
e)
hexokinase.
Q25. In humans, pyruvate
cannot be converted to
a)
b)
c)
d)
acetyl-CoA
lactate
ethanol
oxaloacetate
Q26. The conversion of 1 mol of pyruvate
via pyruvate dehydrogenase and
citric acid cycle yields _______ mol
of CO2, _________ mol of NADH,
______ mol of FADH2, and _______
mol of ATP (or GTP).
a)
b)
c)
d)
e)
3, 2, 1, 1
3, 3, 3, 1
4, 3, 1, 1
3, 4, 1, 1
0, 4, 2, 1
Q27. Which of the following statements
concerning the enzymatic
mechanism of "citrate synthase"
is correct?
a)
b)
c)
d)
e)
Citrate synthase uses an NAD+ cofactor.
The reaction catalyzed by citrate synthase is
reversible.
During the reaction, 1 ATP molecule is consumed.
It is inhibited by ATP and NADH.
It catalyzes isomerization of citrate.
Q28. In which of the following
reactions does substrate-level
phosphorylation occur?
a) succinyl-CoA
b) succinate
c)
succinate
fumarate
1,3 bisphosphoglcerate3-phosphoglycerate
d) Fructose-6-P
e) a
and c
Fructose 1-6-P
Q29. Name an enzyme
affected in vitamin B1
deficiency?
Q30. The citric acid cycle is
also known as the
a)
b)
c)
d)
e)
Krebs cycle.
Cori cycle.
tricarboxylic acid cycle.
a and c.
a, b, and c.
Q31. What molecule initiates the
citric acid cycle by reacting
with oxaloacetate?
a)
b)
c)
d)
e)
pyruvate
acetyl CoA
oxaloacetate
All of the above.
None of the above.
Q32. Which enzyme(s) is (are)
responsible for the following
reaction?
Pyruvate + CoA + NAD+  acetyl CoA + NADH + H+ + CO2
a)
b)
c)
d)
e)
acetyl CoA synthetase
pyruvate decarboxylase
pyruvate dehydrogenase complex
a and b
a, b, and c
Q33. What are the steps (in the
correct order) involved in the
conversion of pyruvate to
acetyl CoA?
a)
b)
c)
d)
e)
decarboxylation, oxidation, transfer to CoA
decarboxylation, transfer to CoA, oxidation
oxidation, decarboxylation, transfer to CoA
oxidation, transfer to CoA, decarboxylation
None of the above.
Q34. In which reaction is GTP
(or ATP) directly formed
in the citric acid cycle?
Q35. Which of the following conditions will
activate pyruvate dehydrogenase
kinase which catalyzes the
phorphorylation and inactivation of E1 in
the pyruvate dehydrogenase complex?
a)
b)
c)
d)
e)
elevated concentrations of NADH and ATP
elevated concentrations of NAD+ and ADP
Ca2+
Insulin
elevated concentrations of acetyl-CoA
Q36. Approximately how many ATP
or GTP equivalents are
produced during one turn of
the citric acid cycle?
a)
b)
c)
d)
e)
10
6
9
12
None of the above.
Q37. The glyoxylate cycle
enables plants to survive
using only
a)
b)
c)
d)
e)
pyruvate.
acetate.
oxaloacetate.
All of the above.
None of the above.
Q38. What reaction serves to
link glycolysis and the
citric acid cycle?
Q39. How many ATP
equivalents are produced
from the total oxidation of
one pyruvate to 3 CO2.
Q 40. How does the term “mad
as a hatter” realistically
reflect the condition?