Name: ).-, ID#: __ ' NUTRITION 313 EXAMINATION #3 April 8, 2009 I. True (T)/False (F) (2 pts each) .. - !.- 1. Oxidation is best described as a process in which an element loses an atom-of oxygen. -r 2. Free radical formation can occur as result of normal cellular metabolism. ___ 3. The richest sources of preformed vitamin A include liver and milk and milk products. ___ 4. People taking anticoagulents should avoid vitamin E supplementation. ___ 5. Because can be converted into retinol, plant sources are referred to as preformed vitamin A. ___ 6. Many anticoagulants inhibit the vitamin K cycle, thereby preventing activation of clotting proteins. ---,-__ 7. All three forms of vitamin A (retinol, retinal, retinoic acid) arestoredin the liver as retinyl esters. ___ 8. The active form of vitamin E is a-tocopherol- the other forms y-, o-tocopherol and a-, y-, o-tocotrienol) do not possess any activity. ___ 9. The active form of a vitamin is usually the form that has the greatest bioavailability. /' 10. An increase in blood pyruvate and lactate levels may be due to a deficiency of riboflavin. / 11. Vitamin C is a good reducing agent, meaning it keeps things reduced by undergoing oxidat,ion; thus, it must continuously be replaced by dietary sources. .--; 12. More storage of vitamin A is predicted in a person with relative dose response (RDR) of 25% than one with RDR of 10%. II. Multiple-Choice (2 pts each) _',--_1. Which of the carotenoid pigments has the greatest vitamin A activity? (a) alpha-carotene (b) beta-carotene (c) gamma-carotene (d) delta-carotene ___ 2. In what cells will you find most of the retinol and vitamin A stored? (a) stellate (b) gallbladder (c) fundus (d) antrum
Transcript
Name: ).-,
ID#: __ ' NUTRITION 313
EXAMINATION #3 April 8, 2009
I. True (T)/False (F) (2 pts each)
~.. !.- 1. Oxidation is best described as a process in which an element loses an atom-of oxygen.
-r 2. Free radical formation can occur as result of normal cellular metabolism.
___ 3. The richest sources of preformed vitamin A include liver and milk and milk products.
___ 4. People taking anticoagulents should avoid vitamin E supplementation.
___ 5. Because ~-carotene can be converted into retinol, plant sources are referred to as preformed vitamin A.
___ 6. Many anticoagulants inhibit the vitamin K cycle, thereby preventing activation of clotting proteins.
---,-__ 7. All three forms of vitamin A (retinol, retinal, retinoic acid) arestoredin the liver as retinyl esters.
___ 8. The active form of vitamin E is a-tocopherol- the other forms (~-, y-, o-tocopherol and a-, ~-, y-, o-tocotrienol) do not possess any activity.
___ 9. The active form of a vitamin is usually the form that has the greatest bioavailability.
/' 10. An increase in blood pyruvate and lactate levels may be due to a deficiency of riboflavin.
/ 11. Vitamin C is a good reducing agent, meaning it keeps things reduced by undergoing irrever~!ble oxidat,ion; thus, it must continuously be replaced by dietary sources.
.--; 12. More storage of vitamin A is predicted in a person with relative dose response (RDR) of 25% than one with RDR of 10%.
II. Multiple-Choice (2 pts each)
_',--_1. Which of the carotenoid pigments has the greatest vitamin A activity? (a) alpha-carotene (b) beta-carotene (c) gamma-carotene (d) delta-carotene
___ 2. In what cells will you find most of the retinol and vitamin A stored? (a) stellate (b) gallbladder (c) fundus (d) antrum
, /
/
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,: 3. Within the nucleus, all trans-retinoic acid and lor 9-cis retinoic acid bind to _ fa;'nuclear retinoic acid receptors (b) mannosylated glycoproteins (c) cell aggregates' (d) transcription factors
(b) zinc (d) iron
i' 4. Which micromineral deficiency interferes with vitamin A metabolism by reducing retinol binding protein?
(a) manganes (c) selenium
---,,---,-_ 5. A genetic deficiency in leads to vitamin E deficiency syndrome. (a) RRR alpha-tocopherol (b) gamma-tocotrienol (c) tocopherol carrier protein in the jejunum Cd) alpha-tocopherol transfer protein in the liver
:.~ .
(6) vitamin E (d) vitamin K
___ 6. Which fat-soluble vitamin has as its principal function the maintenance of membrane integrity?
(a) vitamin D', (c) vitamin A:>
(d) K /
Jc) E
___ 7. For which vitamin is the tolerable upper intake level set because of increased tendency for bleeding?
(a) A',
.~ " 8. Which of the vitamins is consumed in the form of phylloqpi.QQJ1~.from plant foods? (a) A (b)C (c)E Jd)K
___ 9. yritamin K deficiency is most often observed in: {a) newborns. (b) children. (c) adolescents.' (d) old people,
_,--_ 10, For which vitamin is a severe deficiency associated with an increased tendency for bleeding? (a) A (b) C (c) E (d) K
___'II. Imme4iately following a balanced meal that contained vitamin E (such as fortified milk), where would you most likely find most of the vitamin E in the body?
(a) in the portal blood as alpha-tocopherol (b) in the general circulation bound to RBC (c) inside cells as free alpha-tocopherol (d) stored in adipose tissue ~<'
,Ceyin chylomicrons in the lymphatics and general circulation
12. Induction of a protein (i.e" increasing the amount of a protein) via increasing gene expression can be accomplished by:
(a) vitamin A (b) vitamin C (c) vitamin K (d) more than one of these vitamins
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·/ 13. Vitamin C acts as a cofactor by maintainingiIQojn a reduced state in: (a) collagen synthesis. (b) methylation of homocysteine.
.(c) release energy from nutrients. (d) red blood cell synthesis.
p /. 14. Which of the following molecules synthesized with the help of vitamin C underscores the
importance of vitamin C to fat metabolism: (a5 camitine (b) collagen ~/
(c) tyrosine (d) norepinephrine
.'1'. _~_ 15. Thiamin is important to fatty acid synthesis due to its requirement as a coenzyme for the hexose monophosphate shunt enzyme _
___ 18. Cheilosis is a symptom ofa dietary deficiency of which vitamin? (a),retinol (b) ascorbic acid (c) riboflavin (d) thiamin
___ 19. Metabolism of vitamin B6 to the primary coenzyme from, pyridox~l Ph9§pha,te, requires the action of what other B-vitamin? .. ~.-
(a) GSH (b) NAD (c) TPP ~cl) FMN
_,""--_ 20. Which of the following vitamins has a Tolerable Upper Intake Level established? (a) thiamin (b) ribofalvin (c) vitamin K (d) vitamin C
----'__ 21. Erythrocyte glutathione reductase activity is an assay to assess the status of: (a)' thiamin (b)riboflavin ' , (c) vitamin K (d) vitamin C
_~_ 22. In what type of tissue is the largest amount of vitamin E stored? (a) adipose (b) heart (c) lung (d) brain
;i /N'0
'-- 23. Where would you find retinoid X receptors (RXR)? (a) cytosol (b) nucleus (c) mitochondria ,'(d) none of the above
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III. Fill in (blanks) or Briefly answer (4 pts each)
1. Similar amounts of dietary retinoids and carotenoids do not provide the same amount of vitamin A. To develop dietary recommendations, scientists reconciled this difference by creating a standardized measurement based on retinol, called ( 'c' ' ).
2. The synthesis of the specific bone protein osteocalcin is dependent on the presence of two fat-soluble vitamins: vitamin D and ( '-I' ).
3. The active form of vitamin A that regulates cell differentiation through gene expression is ( ).
, , 4. Rhodopsin is the opsin protein after it has been bound to ( ).
5. A 23-year-old woman with a 10-year history of neurologic disease was admitted to the hospital, complaining of s.~~~"~_~~axi,!, titubation of the head, and loss of proprioceptive sense in her extremities. It has been noticed that her symptom may be related with a deficiency of a fat-soluble vitamin. Which vitamin do you suspect? ~,: ( ,,?"' ~-----~--.,.
IV. Although for micronutrients increasing the amount of a protein by directly inducing gene expression is a common mechanism, we have encountered other mechanisms by which vitamins can regulate proteins, such as posttranslational modification. Among fat-soluble vitamins, provide one example of posttranslational modification - be as specific as possible. (10 pts)
