NUTR 543 – Advanced Nutritional Biochemistry
Final Exam 2007
NAME _______________________________
1. Which of the following is a common etiology for hypoglycemia?
A. Poor diet
B. Insulinoma
C. Hyperinsulinemia
D. Excessive exogenous insulin usage
E. All of the above are correct
2. Which one of these symptoms is not an adrenergic symptom?
A. Blurred vision
B. Weakness
C. Nausea
D. Sweating
E. Shaking
3. What is the possible cause of reactive hypoglycemia is our pt. in case study?
A. Poor diet
B. Exogenous insulin usage
C. Excessive carbohydrate consumption
D. Whipple Procedure
E. A and C are correct
4. Individuals with Von Gierke’s disease are deficient in…
a. G6P dehydrogenase
b. Phosphoglucomutase
c. G6P Phosphatase
d. Fructose 1,6-bisphosphatase
5. What Contributes to growth failure in Von Gierke’s Disease?
a. Hypoglycemia
b. Excessive glycogen storage in small intestine
c. Lactic Acidosis
d. All of the above
6. In diet therapy for adults with Von Gierke’s disease, what is the purpose of consuming cornstarch
before bedtime?
a. It is a good bedtime snack
b. It metabolized slower to provide a steady release of carbohydrate
c. It is less easily stored as glycogen in the liver
d. It helps prevent lactic acidosis
e. None of the above
7. What is the proper progression of Alcohol Metabolism?
a. Ethanol: alcohol: aceylaldehyde: acetate
b. Ethanol: alcohol: acetate: acetylaldehyde
c. Alcohol: ethanol: acetate: acetyladehyde
d. Alcohol: ethanol: acetylaldehyde: acetate
8. Which of the following statements is true about alcoholic hepatitis?
a. Frenchman have a 20% increase of being diagnosed with alcoholic hepatitis
b. Vitamin C supplements enhance thiamin uptake in small intestines
c. NAD levels increase much more than NADH resulting in excess condensation reaction in
the mitochondrial membrane
d. ALT and AST alone are not adequate for diagnosing alcoholic hepatitis
9. Which of the following best describes major nutrient deficiency in a person with Alcoholic
Hepatitis?
a. Low folate, Thiamin, Vitamin A, Iron
b. Low folate, vitamin B-9, Vitamin B-1, biotin
c. Low folate, arachidonic acid, vitamin B-5, iron
d. Low iron, vitamin C, folate, biotin
10. Which of the following is not a consequence of metabolic stress?
a. Increased levels of plasma glucagon
b. Low blood glucose levels
c. Shifts in fluid balance
d. Increased protein use
11. What is the main fuel source after trauma?
a. Ketones
b. Fatty Acids
c. Amino Acids
d. Glucose
12. Adequate nutritional support in trauma patients can still result in protein energy malnutrition
because of
a. Increased basal metabolic rate
b. Prolonged bed rest and decreased mobilization
c. Increased protein catabolism
d. All of the above
13. Phenylketonuria occurs when a person has deficiency of
a. Tyrosine aminotransferase
b. Phenylalanine carboxylase
c. Tyrosine 3-monooxygenase
d. Phenylalanine hydroxylase
e. Two of above
14. Phenylalanine is precursor of
a. Tyrosine, alanine, lysine, pyruvate
b. Alanine, glycine, PAH, BH4
c. Tyrosine, dopamine, noradrenaline, adrenaline
d. Tyrosine, dopamine, adrenaline, alanine
15. What food(s) listed would not be restricted for a person with PKU to have?
a. Diet soda
b. Cornstarch
c. Peanut butter
d. Pasta
e. B and D
16. Which treatment was most effective in treating PDH deficiency according to the case study?
a. Thiamin
b. Biotin
c. Lipoic acid
d. Vitamin C
17. Which metabolite does NOT increase in PDH deficiency?
a. Lactic acid
b. Pyruvate
c. Alanine
d. Carbon Dioxide
18. Which coenzymes play a role in the PDH complex?
a. Thiamine pyrophosphate (TPP), lipoic acid, FAD, NAD, CoA-SH
b. Biotin, vitamin B6, vitamin B12
c. Vitamin C, vitamin D, vitamin E
d. None of these play a role
18.
a.
b.
c.
d.
What is the most widely accepted, proposed underlying mechanism of homocystinuria?
Increased oxidative stress
Abnormal S-adenoslymethionine to S-adenosly homocysteine ratio (SAM:SAH)
Decreased antioxidants
Both A and C (NOTE THAT THERE ARE TWO #18’S ON THIS TEST!)
a.
b.
c.
d.
e.
Which of these is NOT used to treat B6-nonresponsive homocystinuric patients?
Surgery to correct dislocated lens
Low methionine diet
Cysteine and betaine
B6, B12, folic acid
All of the above are used for treatment
19.
20.
Vitamin B6 responsive patients can use vitamin B6 because:
a. Pyridoxine reduces the amount homocysteine by deaminating the sulfide bond.
b. There is enough cystathionine β synthase activity to make cysteine
c. It is used to convert homocysteine back to methionine
d. Vitamin B6 makes the bad, bad things go away.
21. In fructose malabsorption or dietary fructose intolerance, what is the primary cause?
a. Deficiency in aldolase
b. Deficiency in fructokinase
c. Deficiency in SGLT transporter
d. Deficiency in GLUT 2 transporter
e. Deficiency in GLUT 5 transporter
22. Which is the best way to diagnose fructose malabsorption?
a. Liver biopsy
b. Fructose intolerance test
c. Hydrogen breath test
d. Intestinal mucosal biopsy
23. Identify one or more inborn errors of fructose metabolism.
a. Fructokinase (FK) Deficiency
b. F-1,6- Bisphosphate Deficiency
c. F-1-P Aldolase Deficiency
d. Both A and B
e. All of the above
24.
Which of the following does not describe one of the five classes of defective mutations expressed
on the LDL receptor gene in familial hypercholesterolemia type 2a?
a) The LDL receptor fails to move from the endoplasmic reticulum to the golgi apparatus where it
undergoes an important conformational change that allows it to move to the cell surface.
b) The receptor and ligand do not separate post-internalization, and receptor fails to recycle to outer
surface of membrane.
c) The newly synthesized LDL receptors reach the cell surface, but fail to bind LDL.
d) The LDL receptor is recycled to the cell surface, but is too weak to bind LDL.
25.
Please choose the correct sequence in which high LDL cholesterol results in development of
atherosclerosis and CAD.
a. Defective LDL receptors do not bind LDL, LDL becomes oxidized, inflammatory response is
initiated, scavenger receptors on macrophages bind oxidized LDL, foam cells are formed, fatty
streaks lead to atherosclerosis & CAD.
b. Defective LDL receptors do not bind LDL, LDL becomes oxidized, scavenger receptors on
macrophages bind oxidized LDL, foam cells are formed, inflammatory response is initiated, fatty
streaks lead to atherosclerosis and CAD.
c. Defective LDL receptors do not bind LDL, inflammatory response is initiated, LDL becomes oxidized,
scavenger receptors on macrophages bind oxidized LDL, foam cells are formed, fatty streaks lead to
atherosclerosis and CAD.
26.
a.
b.
c.
d.
Which of the following is the most abundant antioxidant found on LDL?
Vitamin C
Vitamin E
Beta-carotene
Vitamin B-12
27.
Pyridoxal phosphate is a cofactor for which of the following reactions:
a.
carbamyl-phosphate synthetase
b.
ornithine transcarbamylase
c.
transaminases
d.
pyruvate dehydrogenase
e.
benzoic acid synthetase
28.
In order for the nitrogen in alanine to be incorporated into the urea cycle, which specific sequence
of enzymes are required for this to occur?
a.
glutamate transaminase, glutaminase
b.
glutamate dehydrogenase, glutaminase
c.
carbamyl-phosphate synthetase, aspartate transaminase
d.
aspartate transaminase, ornithine transcarbamylase
e.
glutamate transaminase, aspartate transaminase
29.
Within an hour after eating a meal, the predominant amino acids found in the blood are:
a. Alanine
b. Phenylalanine
c. Glutamine
d. Aspartate
e. Branched chain amino acids
30.
Which of the following chemicals when administered orally has been shown to be useful in
treating hyperammonemia?
a. Phenylpyruvate
b. Benzoic acid
c. Glucuronic acid
d. Bile acid binding resins
e. Alanine and glutamine
31.
Describe how the periportal hepatocytes and the perivenous hepatocytes work together to
maintain very low levels of ammonia in the peripheral blood
Periportal hepatocytes have high activity of urea cycle enzymes.
CPS, the rate limiting enzyme of the urea cycle, has a Km that allows
it to not be saturated under normal conditions. This allows these
cells remove much of the ammonia in the portal blood and hepatic
artery. In addition, glutamine flowing into the liver is deaminated and
further provides substrate for CPS.
Perivenous hepatocytes have a high activity of glutamine synthetase
which has a low Km for ammonia. This allows these cells to remove
the ammonia that was not converted to urea in the periportal
hepatocytes
32.
Describe how a genetic deficiency in the activity of ornithine transcarbamylase (OTC) results in
an increase in the levels of blood ammonia and alanine and causes arginine to become an essential
amino acid.
OTC catalyzes the condensation reaction between ornithine and
carbamyl-phosphate forming citrulline. This is the reaction that
brings ammonia into the urea cycle. A deficiency in OTC prevents
this from occurring and consequently results in a build-up of
ammonia. Alanine also builds up as the equilibrium reactions of the
transaminases and glutamate dehydrogenase pushes those reactions
towards alanine. Arginine becomes an essential amino acid because
the urea cycle enzymes can also be used to synthesize arginine in the
kidneys. With low OTC activity, this pathway is also substantially
reduced.