Transcript Theory41_54

BCHM2072/2972
2004 THEORY PAPER
MCQs
41 - 54
41. Graph
% Activity/ concentration
The graph below does NOT represent:
120
100
80
60
40
20
0
0
0.5
1
1.5
2
2.5
3
Tim e (days)
F
T
T
T
T
A. The rate of glucose output from the liver
B. The liver glycogen content
C. The activity of muscle pyruvate dehydrogenase
D. The blood insulin level
E. The intracellular liver concentration of fructose 2,6
bisphosphate
42. Glycogenolysis
Which statement regarding the stimulation of glycogenolysis
during starvation is INCORRECT?
T A. Phosphorylase kinase phosphorylates phosphorylase
T B. cAMP-dependent kinase is not activated by
phosphorylation
F C. One phosphorylase molecule is activated for every one
glucagon molecule that binds to a liver glucagon receptor
T D. Glucagon does not stimulate a rise in [cAMP] in muscle
T E. Muscle cannot convert glucose 6-phosphate into glucose
for release into the blood stream
43. WAT & starvation
Which statement regarding white adipose tissue after three
days of starvation is CORRECT:
F A. Phosphodiesterase will be fully active
T B. Hormone sensitive lipase will be phosphorylated
F C. The release of fatty acids into the blood stream will be
decreasing relative to day one
F D. The rate of glycerol release is enough to sustain the
production of 120 of glucose per day
F E. cAMP-dependent protein kinase will be inhibited
44. Fuel stores
Which of the following statements regarding our fuel stores
is INCORRECT?
T A. In the early post-absorbtive period, the brain uses about
120g of glucose per day
F B. Fatty acids are released once all body glycogen stores
have been used up
T C. Although we store most of our energy as fat, we cannot
convert fatty acids into carbohydrate
T D. Net gluconeogenesis is possible from part of
triacylglycerol
T E. The brain cannot use fatty acids as they do not pass
across the blood-brain barrier
45. Cori cycle
The Cori-Cycle to operates when:
T
F
F
F
A. Liver phosphoenolpyruvate carboxykinase is activated
B. Liver pyruvate carboxylase is inhibited
C. Muscle beta-oxidation is inhibited
D. Glucose transport into muscles is prevented
F E. Muscle pyruvate dehydrogenase is stimulated
46. Beta-oxidation
Which statement regarding the process of beta-oxidation is
CORRECT?
F A. The transport of fatty acids into the cell is totally
dependent on a membrane carrier
F B. The movement of fatty acids into the mitochondrial matrix
is stimulated by malonyl CoA
F C. The beta-oxidation of a 16-carbon fatty acyl CoA would
result in the production of 8 FADH2 and 8 NADH
molecules
F D. Matrix carnitine and cytosolic carnitine pools cannot mix
T E. The coupling of fatty acids to Coenzyme A involves
consumption of ATP
47. Scanning check
As a check on the scanning procedure enter an answer of
A to question 47 on the answer sheet.
Table
Use the Table below to answer Questions 48-51
Options A-E show the rates of various enzymes and pathways
during exercise.
The scale goes from minimum (-) to maximum (+++++).
Lots of
glycogenolysis
and next to
nothing of
anything
else!!??.
Low fatty acid
oxidation but
plenty of
carbohydrate
oxidation – all
the way to CO2
Low rates of
fatty acid
oxidation –
little carb
oxidation
Lots of fatty
acid oxidation –
reasonable
carb oxidation
including some
glycogenolysis
Lots of
glycogenolysis
accompanied
by glycolysis
Activity
A
B
C
D
E
beta-oxidation of
fatty acids
-
-
++
+++
-
Krebs cycle
-
+++
++
++++
-
Muscle
+++++
+++
-
+
+++++
Muscle
Phosphofructokinase
+++
-
++
++++
Muscle pyruvate
dehydrogenase
++
-
++
-
phosphorylase
-
48. 30 minute jog
Which option (A-E) shows the pattern of fuel
utilization after 30 minutes of jogging
(moderate, aerobic exercise)?
Low rates of
fatty acid
oxidation –
little carb
oxidation
Lots of fatty
acid oxidation –
reasonable
carb oxidation
including some
glycogenolysis
Activity
A
B
C
D
E
beta-oxidation of
fatty acids
-
-
++
+++
-
Krebs cycle
-
+++
++
++++
-
Muscle
+++++
+++
-
+
+++++
-
+++
-
++
++++
-
++
-
++
-
phosphorylase
Muscle
Phosphofructokinase
Muscle pyruvate
dehydrogenase
49. Sprint
Which option (A-E) shows the
pattern of fuel utilization during a
sprint?
Lots of
glycogenolysis
accompanied
by glycolysis
Activity
A
B
C
D
E
beta-oxidation of
fatty acids
-
-
++
+++
-
Krebs cycle
-
+++
++
++++
-
Muscle
+++++
+++
-
+
+++++
Muscle
Phosphofructokinase
+++
-
++
++++
Muscle pyruvate
dehydrogenase
++
-
++
-
phosphorylase
-
50. 1 hr marathon
Which option (A-E) shows the pattern of fuel
utilization after 1 hour of running in a
competitive long distance race (eg a marathon
race)?
Lots of fatty
acid oxidation –
reasonable
carb oxidation
including some
glycogenolysis
Activity
A
B
C
D
E
beta-oxidation of
fatty acids
-
-
++
+++
-
Krebs cycle
-
+++
++
++++
-
Muscle
+++++
+++
-
+
+++++
-
+++
-
++
++++
-
++
-
++
-
phosphorylase
Muscle
Phosphofructokinase
Muscle pyruvate
dehydrogenase
51. Impossible
Which option (A-E) is NOT possible
under any exercise scenario?
Lots of
glycogenolysis
and next to
nothing of
anything
else!!??.
Activity
A
B
C
D
E
beta-oxidation of
fatty acids
-
-
++
+++
-
Krebs cycle
-
+++
++
++++
-
Muscle
+++++
+++
-
+
+++++
Muscle
Phosphofructokinase
+++
-
++
++++
Muscle pyruvate
dehydrogenase
++
-
++
-
phosphorylase
-
52. Dietary protein
What is NOT one of the fates of amino acids arising from
the digestion of dietary protein?
A. Deamination to produce carbon skeletons
B. Conversion to glucose in the liver
C. Synthesis of new protein
D. Conversion to fat in the liver
No E. Conversion to alanine in the muscle and storage as
poly-alanine
Is
Is
Is
Is
53. Protein intake
For a 60 kg female, which of the follow type of protein
intake would be LEAST desirable?
OK
OK
NO
OK
OK
A. 240 g/day of protein comprised of all amino acids
B. 60 g/day of protein comprisedof a all amino acids
C. 120 g/day of protein deficient in lysine
D. 120 g/day of protein deficient in alanine
E. 60 d/day of protein deficient in both alanine and
glutamate
54. Krebs cycle
Which statement regarding the Krebs Cycle is CORRECT?
F A. Complete oxidation of one acetyl CoA in the Krebs Cycle
produces 4 NADH and 1 FADH2
F B. The major rate limiting steps are the reactions from
succinate to oxaloacetate
F C. The sequence of reactions from succinate to
oxaloacetate are similar to those involved in fatty acid
sythesis
T D. The Krebs Cycle does not produce any ATP directly
E. During one turn of the cycle, neither of the carbon atoms
F
released as carbon dioxide have come from the acetyl
CoA molecule that entered the cycle